do you take you car to a track? if so go with the 1/8th scale. if you bash and track the car go with the slash 4x4..... but check out jammin scrt10 or the ofna sc10.. based on a 8 scale chassis but made for short course...
as for the revo 1/16 they are fun but they get old quick, too small of a car to handle high speeds and aggressive jumps