Welcome to the club Sich
I personally got also stuck on Manjaro. You get the latest software avaiable and as mentioned before you can always draw missing packages from the AUR. Manjaro is to Arch a little bit like Mint is to Ubuntu.
I started with Linux with Ubuntu 12.04 and learned the most basic things first having no Linux experience at all. As you are a Debian server admin you should feel right at home there. PPAs can be used with any Ubuntu derivative, best added thorugh the terminal. As time went by I wasn’t able to find PPAs for some particular pieces of software or they weren’t updated for the next version of Ubuntu rendering them unsusable after an upgrade. That’s the reason I switched to Manjaro somewhere around the start of 2015. Arch is nice, but a little too technical for my taste, which is what Manjaro circumvents with userfriendliness. I installed Arch on my netbook (Asus EeePC 1000H) and it took me a couple of hours with the installation guide, but I couldn’t get some things working correctly. This is where Manjaro just worked out of the box like Ubuntu does with the difference of not having to upgrade every 2 or 4 years.
As for the package management in Manjaro it’s ‘pacman -S *’ instead of ‘apt-get install *’, but that’s not too much of a problem. The pamac GUI is easy to use and not as cluttered as synaptic or the Ubuntu Software Center, though I prefer the command line.
As for the desktop itself, it’s more a matter of taste. As far as I’m aware the barely a performance difference between the major ones (Gnome, XFCE, LXDE, KDE). Personally I run XFCE for the versatility, usability and panel plguins. Though the XFCE compositor is meh at best. I use compton with the config found at the very bottom here on LGC’s site: https://linuxgamecast.com/2018/05/linuxgamecast-weekly-301-giggletron-9000/
It should work on any system flawlessly, but just in case you still have a little stutter or it’s not smooth, edit the ~/.config/compton.conf file and change glx-swap-method from “0” to anything from 2 to 6. 1 (copy) caused a flickering desktop for me on NVidia.
So much for “Yeah, go with Manjaro!” in a little more than 2 or 3 sentences…