Wow, there’s quite a list of differences. 
For starters, PCLinuxOS is allergic to systemd and still uses sysvinit as its PID 1. They’re also somewhat allergic to sudo, although I can understand their objections to the default configuration that sudo ships with, because this default configuration is inherently insecure. I’m not going to get into the details here because this is not a support thread, and I’ve already explained this elsewhere on the forum.
In addition to that, they use apt-rpm for their package management — as you said, .rpm packages but managed via apt and synaptic — whereas Manjaro uses Arch’s pacman, or alternatively, pamac, which is compatible with pacman.
I think they’re also allergic to Wayland, while Manjaro offers both Wayland and X11.
Release-wise, both PCLinuxOS and Manjaro are rolling-release distributions, but Manjaro is curated. Barring any urgent security updates and (usually security- or stability-related) fast-tracked packages, updates in Manjaro are bundled together and percolate down through Manjaro Unstable and Manjaro Testing into Manjaro Stable.
Every bundled update comes with a dedicated announcement thread under the Announcements category. Each of those threads details the changes in the first post, and any potential problems (and how to deal with them) in the second post. And in spite of our ever-ongoing efforts to elucidate the n00bs, it would still appear that nobody reads them, judging by the swathes of “Haaaalp, it not wurkz!” threads that are all about the same thing, for which the solution was offered on the announcement threads. 
And of course, Manjaro also offers access to the AUR — the Arch User Repository, which contains build scripts for additional software. We do not officially support the AUR because its software is entirely uploaded by Arch community members and there is no guarantee that it’ll work, that it’ll continue to be maintained, and/or that nothing nefarious is being uploaded there — which has already happened in the past. And in addition to that, Manjaro also supports FlatPak, Snap and AppImages, even though we do not recommend the use of any of those formats.
Manjaro is more user-friendly than Arch proper, but in being Arch-based, it is still pretty much a hands-on distribution that requires periodic manual intervention, such as when there are .pacnew files. Manjaro must also be kept up to date as a whole, because partial updates are not supported.
One of the other differences is that Manjaro lets you use a kernel of choice, as long as said kernel is still supported upstream — i.e. long-term-support kernels and the current mainline kernels. Upon updating your system, it is then also quite common for your kernel to get updated, but it is important to realize that these are only maintenance updates, and not kernel version bumps. So for instance, Manjaro will not upgrade your 6.6 kernel to 6.7, but it will for instance update — fictional numbers here — 6.6.10 to 6.6.12.
In light of the above, it is therefore also important to never interrupt an update, because the update process removes the installed kernel images and initcpios from /boot at the start of the update process, and will only install the new kernel images and initcpios, and update the boot loader at the end of the update process. Therefore, interrupting the update will result in an unbootable system.
Luckily, the Manjaro live image can always be used to offer repair options and/or complete an interrupted update. And naturally, we strongly encourage everyone to make backups. timeshift is included by default — also in the live ISO — but there are yet other very capable backup solutions in the repository.
I think I’ve covered about the most important stuff here, but it also deserves mentioning that the Manjaro Wiki, the Arch Wiki and the Tutorials section of the forum are valuable information sources. 
Thanks. I will start reading the announcements. i will look at the wiki again. i could not see a lot there. must have missed the nav section.
you have been helpful!
found an 8 years old laptop (in storage room)and since i havent really owned a laptop before i was happy but windows wasnt running very well and also since i knew about a linux disto named as kali i planned why not download that instead but before i even downloaded it, very quickly I found out its not for newbies and than randomly came across manjaro and after 3 weeks of using it, im here XD
my name is Enzo and i have never used linux before or owned a windows machine also i got 4GB ram and shii but hey at least it works
all i do is watch anime, study python, social media, yt and stuff so even tho this laptop is crap, its doable 
Not realy new to Linux, played around a while ago with Ubuntu ( 5 or more years ago). Started with Manjaro on an older Thinkpad. Now all my machines run Manjaro, xfce on pc, kde on Laptop. Both run fine for the Moment. Case of use is : browsing, mailing, gaming, video editing…
I’ve been using linux since about 1996, debian, ubuntu, gentoo, redhat, fedora, suse, opensuse, and a few others now defunct. Mostly xfce4 based, although kde and gnome have also appeared on my desktop. Currently have about 5 distribution installs on my current laptop.
Salut,
Permanently shifted to linux. Tried out a whole bunch of distros, but manjaro was the one.
I appreciate the devs for what they have created. And I would like to give back to the community as well as manjaro.
2nd year CS Major. Tell me a way to actively learn manjaro and master it. I see myself helping the development of manjaro. help me making the dream come true
I have been using manjaro since 6 yrs now. Started using it cause I needed a rolling release and been then there was only arch and then Manjaro, as Manjaro was very user friendly to installed and then a very welcoming community through this forum.
Now I am a contributor to Manjaro Arm and all my devices have Manjaro on it.
Interesting. We should discuss video editing on a different thread.
I use kdenlive and I and very new to it.
Hello everyone,
I’m Nico from Germany.
I started using Linux Mint 2 years ago to learn Linux and C programming. When I completely nuked that installation I made the decision to completely commit to Majaro. It has mostly been a breeze so far and I’m delighted to see how many things just work.
I’m looking forward to solving problems with you!
Hi, I’m an old gray-bearded Linux user (for several decades now). By the way, I have been using Arch for 5 years now. I bought a nice little RPi5. Right now Arch is booting but I could not get graphics (X11) to work. This lead me to give Manjaro/ARM a try. I am a Manjaro newbie !
Hello everyone,
Long ago I got annoyed in Windows OS because of its instability, vulnerability and frequent crashes. So I tried to switch to Linux and install some distros. Manjaro Xfce is the only distro worked with my laptop without any errors or issues. Until now my primary and daily driver is Manjaro Linux. It is simple and straightforward that’s why I love Manjaro. Interested in Arch too but will only try it once I have a lot of extra time and knowledge about Linux.
I’m using multiboot in a single HDD, one manjaro as my daily driver, one kali because I’m quite interested in security stuff, might learn someday, and one windows 10 pro for gaming.
I’m glad Manjaro is the first and only one that worked on my laptop when I needed a distro the most. It made my life easier compared when I’m still using windows.
Anyway I’m just new here, thanks for those who’s helping me and giving me tips. I’m also willing to help in future once I have enough knowledge with Linux and this distro itself. 
Use it, and nothing else. That’s the best way to learn, IMHO.
Hi all, may as well introduce myself.
I’ve been daily driving Linux for quite some time now (since about 2009, I think), and have more or less moved away from Windows now that Proton is basically working, as I’m not thrilled with the general bloat of Windows (according to my PSU, this bloat is currently running at about 10-15W of extra idle power consumption). I jumped from Ubuntu to Manjaro for two reasons: 1 - Snaps not being a great user experience (fantastic server software doesn’t always translate to fantastic desktop software) and 2 - Needing access to at least kernel 6.6 for power management fixes on RDNA3 GPUs.
As a fairly old hand with Linux I shall try to answer more questions that I ask 
Hello everyone,
I’ve been using Linux distros for quite a few years and Manjaro for the last 2. I’ve never really gone deep but I’m constantly learning.
Thanks to everybody for maintaining it and offering help to those who ask for it.
Hi, I am Jack!
I am an amateur Linux user.
I have switched to Manjaro very recently and have not used it before.
Looking forward to talking to everyone on the forum!
And i give lots of credit to the Manjaro Team for creating this super nice Linux distro!
Hi,
I have come back to Manjaro after a a 12 year break during which I have experimented with different Arch-based distros. I stopped using Manjaro during a period of transition, where it seemed to have lost direction. I played around with arch-based installers and helped out a little on the Architect forum until Carl Duff decided to drop the project. I seem to have turned full circle and I have been pleasantly surprised with the current release which was easy and fast to install.
Back to Manjaro after a few years distro hopping other Arch flavors. Currently using Manjaro Gnome and both me and my kids are loving it.
Also decided to really test Flatpaks this time around. After installing a couple dozen flatpaks I’m surprised at how smooth everything is running.
i was wondering, are there any hangouts for Manjaro users? It use to be the forum before there were changes and it appears the forum is focused on being a technical site now.
It’s telling me that page doesn’t exist
Whoops
I suspect you’re not yet Trust Level 1, seeing as I’m there right now:
https://forum.manjaro.org/c/member-hub/117
Don’t worry, if you stick around, you’ll soon be Trust Level 1.
I meant Trust Level 2, sorry.