I recently sold my Traxxas Slash 2wd, it was a great fun truck just slightly modded. Velion motor VXL ESC, LCG chassis and aftermarket A arms and shocks. It even survived a high speed tag of a fence post that sent it spinning on it's roof and kicked my night driving light out.
I drove a bunch of my buddy's 4wd short course trucks, and the biggest thing I noticed is that the 4wd trucks come out of the hole harder and corner a bit better on the throttle. If money is no object and you want something different, there's the Axial Racing SCORE Trophy Truck, which has a solid rear axle and handles totally different than any other short course truck. Hit up your local RC shop and chat up the guys behind the counter, the ones locally were more than happy to let me test drive their shop demos and a few of their personal rigs.