Ubuntu is just too dated for development work IMO - I need to rebuild everything from source or find 3rd party PPA for anything remotely recent - I'm fine with compiling deps for production but for development the distro really shouldn't be getting in my way of trying new stuff out.

That said I've had many performance issues on GNOME - I like the way it looks and the "feel" and I got used to the UI over the last year or more but frankly it's constantly hogging my PC down, both desktop an laptop - when I switched to KDE/plasma 5 I saw my WebGL chrome app go from 40-50 FPS to consistent 60 FPS - both tests done after a clean start and simply starting the app letting it run for a while. The entire system feels more responsive - can't trace the issue but the results are measurable and noticeable

I've had flicker and stability issues with KDE 5 when I last tried it a year ago but now it appears quite stable. My only complaint is that themes/design community are nowhere near to Gnome.

LTS or the other versions?

Any distro with a release schedule is going to have caveats about not having prebuilt packages for the latest XYZ. The only things I can think of that might give you a faster update schedule than Ubuntu (in terms of newer versions, not just point releases) would be Fedora, Arch, or Gentoo.

Even the standard releases are too stale, in LTS dev tools and compilers are ancient.

I've forgot to mention I've moved to Fedora a year or two back for this reason - got tired of rebuilding/PPA hunting for every part of my OS when I want to use the latest version of tool/lib X.

And once dependencies are too old (very often) prepare to be rebuilding 5+ custom libs and figuring out the differences between debian package/path layout and what the library build uses ... so much wasted time.