Ok so I'm finally gonna start racing, and need to upgrade my Spektrum DX 3.0. I was looking at either the 3pk or 4pk. I'm only gonna race two classes for now, mt and 1/8 buggy, and was thinking the 4pk is overkill for me. Is the 3pk good enough? I know the 4 is fast, is the 3 fast enough? And i sure don't need all the features the 4pk has on it, but that radio will prolly be my last for years to come. Advice? Thanks...