I agree, thanks to everyone involved!
In this world, with my progressing age, I don't like hectic stuff, so Mageia 9 is awesome just because of that.

Anyway, my short experience so far.
I use Gnome as a main DE, but I also like Openbox a lot, so it's being used as well. Mageia may not be so KDE centric as before, but it is still slightly favoring this DE, but without any negative impact on the rest, so no problem. I also use only DNF, not URPMI, again, since it works flawlessly, no problem.
Installation was simple, no problems encountered with one exception - boot loader installation failed at the end. I didn't touch partition layout apart from formatting existing partitions, so I don't know.
So I did new fresh install with creating new partitions, although they were the same with just slightly different sizes and it went just fine this time. I haven't checked bugzilla for this yet, will do it later.
Installed system works perfectly fine, no problems here so far. Yeah, Nvidia (mainly Turing) GPUs flicker on top of the screen randomly, but it's a known issue with the proprietary driver since about v525, Nvidia is actively trying to fix it. In my case, it's mostly no problem as it almost doesn't happen, so it doesn't bother me as much.
Everything else is just like in M8 so far, just Gnome is newer. It also means it's a combo of GTK3 and GTK4 themes and it's somewhat incoherent. Using adw-gtk3 theme fixes that perfectly. I noticed in Errata, that nm-applet doesn't report connection status properly, but that's not true in my case, as it works as it should, which is great.

All my HW works just as it did, only scanner doesn't. Well, not Mageia's fault, it just died.

I don't use smartphones, so I will need to get a replacement that works in Linux though.
Well, that's about it. Again, thanks to everyone behind the release, great job!