If you like to go fast and don't care about the big price diff. then get the brute. I have a 09 750i and there is noway I'd buy a rancher, unless it was for my 12 yr old or my o'lady. Not saying there is anything wrong with a rancher, I think it's a great quad, my buddy has one, I'm just spoiled by the power and ride of the brute. If you get a rancher just get the es 4x4 not the auto, I've read about it and it sound like junk. A 5speed with rev. will be more fun, and if you get a brute having a belt isn't bad, you're alawys in the right gear and if you take care of your shit your belt won't get wet. I've had mine up to the seat in water and never had a problem.
Wossner 12.5:1 416 piston, Stage 2 hot cam, kibblewhite valves and springs, mild port job, billet clutch basket, Curtis Sparks ceramic coated exhaust, 1 down 1 up gearing, razr 2 fronts HD rears, powder coated (white) and gusseted frame, works tr front shocks, bunch of Pro Armor, ect. ect.