If this is a first brushless, I would start out with the 4600kV... I started with the 5700kV and ended up breaking TONS of parts. Besides that, I still toned down the timing in the ESC with the 5700kV to "Lowest" to reduce the RPM on it...
It feels good now, but the 5700kV is WAAAY too much motor IMO... If you're a basher and want some pure speed and tire smoking, get the 5700kV or the 6600kV version.
RIP TAP RC