First, I have a R7-240 VGA-Card installed and I think the Catalyst is too old for this Card to bring it to 100% working.
The second thing is, that Xorg-server is locked to Version 1.18, while Catalyst cannot handle newer Versions.
With AMDGPU I have the Latest Version.
Sometimes I have Screen Tearing when I watch Videos with Catalyst, not with AMDGPU.
I don't play Games with this Card, so I cannot say something about that.
After 1 Day Office work and watch two Videos, I can say it is working better.