We've done FWD, RWD, and 4wd in my family and you're right, you don't need 4wd, but it's a pretty darn nice option to have a available
Usually the first few races of the season have either rainouts, sudden downpours, mid race rain cancelations, freezing cold temps, or the timing system laptop or the transponders have tantrums and freak out. Once we hit July, things tend to go well other than occasionally oppressive heat.