Yes, it runs very well. The only problem is that the launcher can be a bit flakey but I suspect that’s not specific to the Deck.

GTA Chinatown Wars (PSP version) on my Steam Deck. I tried GTAV first and found it a bit lackluster (it’s very well made, but it didn’t really grab me), then thought I’d try Chinatown Wars instead and I’ve been surprised how much I’m enjoying it.

Absolutely yes, Warband is tons of fun and there’s no other game quite like it. The mods are great too, I’ve put so many hours into Floris and Prophesy of Pendor.