Ideally, you should try all of them, but that's probably not possible. They are slightly different and 1 may suit you more than another. I got nowhere with brand X, but went to the top of our local A by buying a Serpent 120L. A great car. At our last race, the top 5 were 12R5. TOP, 12R5, Serpent, CRC. If you're new to 1/12TH it might be well to go with a car used by some of the best racers at your track. That way if you need help, it's available.