I am almost thinking the Assault is a little closer to the Crossfire equipt with a 141x2.25" track (like a powerclaw) than a Full 153 M8 since the Assault is a 146". I guess it kind of splits the difference, but I am super happy with my 09 xfire 800snopro. I really dont think it is as down on power as people think, it is just smooth on the power that it doesn't seem like it has it. Even with the 60/60 gears on the Xfires you cant keep the skis on the snow.
Both sleds look very similar and seem to have similar ergos, but i have never had a chance to hope on a Assualt so i cannot add any input there.
I will be interested to see if Burandt can accomplish similar insanity on the new poo though... not meaning to open a new can of worms or anything.
As for the cat engine (before '10 models) the 800 is one of the industies best in accepting mods and making big power for relatively low dollars... RKT head and bolt on packages, SLP pipe kits and D&D shim kit are just some of the no nonsense mods come to mind when talking low dollar mods making 10+ pony... they just take so good to mods its crazy.