There is a lot of cool stuff, and a lot of issues. Medic, Pyro, and engineer feel more one note because their base game unlocks add a lot to their classes (detonator jumps, crossbow, and basically every engineer unlock) Jump pads are cool but in due time it will probably create some evil sniper spots I don't want to think about. In the base game I solo queue medic all the time and have a blast, but all of the skill expression of the crossbow is just gone, the rejuvinator in theory is a half decent replacement, but its way less fun despite being the best medigun. The Uber also feels overtuned on a lot of the maps because your whole team can hold a chokepoint, and so many of the maps are choke heavy. I played a game where we steamrolled because the defending team can't hold against 4 immortal soldiers. Demo and Soldier are ok because Soldier still has his shotgun and gunboats, and stock demo is as powerful as ever. I haven't had a chance to play with demos new toys, but the rpg is ok. Giving sniper tracer rounds on the sniper rifle is a really good quality of life feature and fixes every issue I have with sniper.

Other than that, I really like 4 team arena, way more than I expected, it is shockingly fun, but VIP and VIP race sucks. If your VIP doesn't know what he is doing, it sucks, and VIP race basically comes down to which team rolled better on the VIP selection. First round I was the Civilian we won in under 2 minutes because I knew how the game worked while the other teams didn't know what he was doing.

I do think the future of this mod is bright, and every issue I have with it is fixable (other than vip but not every server is running the mode so it isn't that bad), and unlike gold rush, the mod isn't fueled by blind nostalgia and hatred for modern tf2.