What's wrong with it? Maybe it's something I could fix.
Lemme see whats maybe broken currently
Soda Popper: No longer grants minicrits, charge pops automatically like old but does not give jumps.
Rechargables (ie guillotine, sandvich): Does not recharge unless you are the correct class (milk and jarate work though)
Baby Face's Blaster: Still uses original instead of updated version Sidenote: switching to secondary or melee will slow you further
Short Circuit: Still uses original instead of updated versions
*Cow Mangler: (Not sure if it's 5 shots or 4 shots in current randomizer, I forget)
*Diamondback: Not sure if it works with backstabs now too in randomizer but its damn difficult to get the proper combinations to test
Mediguns: Not sure if fixable but you cannot pop ubercharge unless you are a medic (I remember you used to be able to on this server but it was for some reason perma-uber)
Also note: Items that grant max health (ie wee booties, danger shield, and Dakolah's Bar) do not heal or give you health, which is problematic in Arena maps.
Dakolah will give you health from like 125->175, but you'll only have 125/175 hp and it will never heal you unless you have a medic or a health kit(which aren't usually around on arena)
Everything else should be working as intended.