My friend that got me into quads has a 400ex and a 450r. The 400ex was the first one ive ever used and it was a ton of fun on the trails. My warrior according to the previous owner is a 420 now, and it kinda shows because it feels quite a bit faster then his 400ex. IMO the 400ex had a much stiffer ride (maybe it was the way the shocks were set), but the warrior feels a lot more predictable, aspecially in rough rocky terrain then the ex did... just my .02