I recall KDE being a mess but that was during the switch to KDE4. This is something I really need to be better about: losing my memories of trouble with things from decades ago. I have the same hesitancy with FUSE.
Oh, KDE Plasma is a completely different animal now. Lightweight (really!) and a pleasure to use as a power user. I also remember the KDE4 days and had firmly placed KDE in the "unusably bloated garbage" bucket, but when I tentatively tried Plasma 5 on my laptop a few years back I said "holy crap" and immediately installed it on everything. Plasma is a gem.