IMO, it all depends on what you already have. I dunno about the new stuff from AE, but if the radio is junk and the servos are junk, you might be ahead to build a roller kit. But, if you have a good radio and servos already, then the RACE KIT is not that that bad of a deal, however, Team Losi RTRs come with a great radio that is DSM, has many racing adjustments and the motor (Mach 427) is a powerhouse of a motor, however a fuel consumer. The RTR chassis looks better on the AE stuff, but i do not know if there radio and motor is worth anything. If you have radio and motor, by roller, if you need radio and motor, buy the kit with the better radio imo.
You will def. need to upgrade servos in the Losi RTR.