I was running an XTM 24.7 and the revo with a 3.3 chassis was pretty much useless... Cool if you like wheelies all day, but bad if you don't like bottoming out off small jumps. The big engine adds weight. When you try to adjust the suspension to deal with the weight, then the revo bounces all over and is useless to drive. Unless your in a skate park. Or just running on concrete at high speeds.
I actually just dropped back down to the 18TM and I'm much happier at a motocross track. Now I need to soften the suspension back up and get some better tires... Well, the tires are on the way, I need to just sit down and rework the thing.