The same way Valve uses user generated content to release weapons, miscs, taunts, maps and even bugfixes (i.e. sigsegv and a few other heroes), they could and should use a lot of leftover/forgotten mods from Facepunch and other repositories to update weapons and player models alike. Aesthetically and optimizing poly counts. It's nice that they've started doing a house cleaning on the game's code to fix a lot of dumb/random stuff, but the game's performance has always gone downhill.