i have both, a nitro rustler and x-terminator. i find my buggy to be much more fun off road. way better handling and it's more durable. my truck i basically use for the street only now that i got my buggy. it's actually a lotmore fun on pavement than my buggy is because its power/wheel ratio is so much more than the buggy's. i can do burn-outs with it, which i can't even come close to doing with my buggy.
basically, having both is the best, but if you cna only have one i'd recmoend the buggy. there's a reason most people call it the ultimate class in rc. they are the bets handling and most durable off-road rc's out there, bar-none. an dif you slap some road tires on and stiffen the suspension a bit, they can be pretty dman good on-road, too. JMO
At our track, it's the buggies that rule. Most guys race them. A few race the stadium truck and some race monster truck, but mostly it's buggies. Buggies are a lot of fun, so I would definitely say get a buggy.
i couldnt decide either. i have a PRP Swift, HPI Nitro MT, HPI Super Nitro, HPI Super Nitro Rallye, and a Smartech Aerohawk. i can never have enough toys. 3 of those cars i can race locally.