I've been a very big Gnome fan in the past (I still love it!), but since Plasma 6, I rebased both my laptop (Silverblue) and gaming PC (Bazzite) to their KDE variant.
Plasma 6 was a huge milestone. Not only for the KDE team and everyone else out there, but also for me. I constantly tried KDE from time to time, but it never "clicked" for me. Gnome always felt more polished and better thought out.
But since I tried Plasma 6, I never felt the need to go back. It looked and felt very high quality, had quite a few nice features Gnome didn't have (the only working fractional scaling, HDR, VRR, Krunner, widgets, etc.), and, most importantly, it felt more robust than previous versions, with less crashes and weird bugs.
The fact that the release schedule seemingly got adapted to a form similarly to Gnome, which is very handy for distros like Fedora or Ubuntu, boosted my confidence in not expecting big changes between releases.
Somehow, that isn't the case tho. It worked relatively fine most of the time, but in the recent time, there are soo many paper cuts accumulating.
Nothing huge, but things like graphical glitches (sporadic colored horizontal lines when switching windows for example), my PC constantly awakening from standby, and so on. The compositor in particular is behaving weird from time to time. I stopped counting how often I lost progress of a game, because it crashed after unlocking my device for example.
What also annoys me a lot is the fact, that there are things changing all the time between releases.
I use Fedora Atomic, namely uBlue.
Bluefin, the Gnome variant, offers a gts variant, where you are always one version behind the latest Fedora release. This ensures a more laid back experience.
I wanted to try that for myself too, but turns out, Bazzite and Aurora (KDE) don't even offer that, because KDE always pushes big changes between updates, which makes that impossible.
For a rolling release, like Arch or Tumbleweed, this is fine. But I chose Fedora (or any other distro with a fixed stable release schedule for that matter) specifically because I want to wait a few months until all bugs are ironed out.
Long story short, I started to think that KDE is somewhat inherently unreliable. Gnome feels more like "one thing", and KDE is more modular, and between the single modules are constant incompatibilities that give me paper cuts. The weird and irregular (for my taste) release schedule introduces constant problems.
Sometimes, I get a bit "nostalgic", and the grass is always greener on the other side. I will try to rebase to Gnome again for a while and see, if it gives me a more chill experience.
Don't misunderstand this "rant" as hate or something against KDE. It's unbelievable how much better both got this year alone, and I'm just incredible thankful what the developer teams of them have achieved.
I will start year 2025 with the best hopes and a lot of optimism for what will come!
(P.S.: I will of course try to catch and report all bugs I mentioned)
Personal experience - I used some late version of Plasma 5.2x on desktop and now Plasma 6.x of course (always Wayland, generally always the latest stable version available), and Gnome (always Wayland, always the latest stable version) on my work notebook. I've never experienced any "serious" bug on Gnome, but I have experienced multiple on Plasma over that time period. I think the most "serious" bug I've had on Gnome was that the cursor was flipped upside down for a while until they fixed that (some time ago). While the most serious bug in KDE were multiple crashes in plasmashell since Plasma 6.x. (Meaning all your open apps got closed, I'd say that's pretty serious for a bug). Another smaller bug, very recently, was that virtual desktops in KDE Plasma were named wrong and when I renamed them they didn't get saved so it reverts to the wrong names (e.g. "Desktop 1", "Desktop 3", "Desktop 4", "Desktop 4"). But it seems they fixed that with the latest update as well.
Which is also why I'd like to keep it that way, Gnome for work and KDE where it's not super important if plasmashell crashes or does some weird thing every once in a while. I think KDE is more prone to bugs because it's simply more complex than Gnome. Gnome is quite minimalistic and doesn't offer lots of features, KDE is a powerhouse desktop with literally tons of features, dwarfing probably every other desktop environment, at least in the available options for which a GUI exists to set them. Also, Gnome doesn't support many advanced features like HDR (yet), while Plasma does. So the complexity in having all that stuff means Plasma must be more prone to bugs.
So I view KDE Plasma as "slightly more buggy" than Gnome, still. Especially for dot-zero releases. But the KDE devs are also improving it all the time, so it might become more stable soon. But still, for personal use, KDE Plasma is "stable enough" despite those mentioned bugs, some of which were also fixed in the meantime. For example I didn't have any more plasmashell crashes since they said that they fixed those causes. Which is why I'm using KDE Plasma 6.x for my personal machines. I like it more than Gnome, but when I want "100%" reliability for a DE, I'm still using Gnome. The main thing I dislike about Gnome isn't actually its UI or design philosophy or even the limited GUI-based options it offers, but rather its philosophy regarding standards or compliance or making interoperability easier. The Gnome devs often do their own thing and don't play that nice with others.
What always irritated me about Gnome was that when Mutter crashed, I lost anything I was working on. When Plasma crashes, it'll bring my applications back. The GC bug Gnome had for years was what pushed me to KDE because I couldn't trust it to not nuke whatever I was working on. Never looked back.
Well, that and the Gnome devs thinking they know how everyone needs to use their DE. That was fucking irritating, especially when they'd break extensions with nary a care.