Well, the NTC3 RTR only has a single-speed and a Roar-legal .12 motor compared to the Yok GT4RTR which has a two-speed and is running a .18 . . .which is going to be faster out of the box?
So, question may be - are you going to race it? I can tell you that if you bring a GT4RTR to a track and try to race it, the guys running their .12's are going to be just slightly irritated with you. . . and, in many series and races, two-speeds are not legal until "Expert" level classes. (I know that Hobby People series in Southern Cal is this way)
So, if you want to race, prolly either get the GT4 and lockout the second speed and change motors or get the NTC3 and just start racing. . .
I've owned both and both are very good cars (I bought the kits.)