I would pass on the Warrior if you're into doing more than going slow on flat trails. That is 20 year old technology you're dealing with. But they are EXTREMELY dependable, maybe even bulletproof. Back in the day, they were considered to be high performance.
I'll put in my vote for the Suzuki LTZ400 and the Arctic Cat DVX400 (same machine, different plastic). Or for a little more, get a KFX450R.