What is the different between Traxxas 3300 vs Castle Creation 7700, or 2200?

I have notice some 2200 or 3300 have so much power and speed. Thanks

None of those are the same physical size motors - TRX 3500 is 380 size (smallest), Castle 7700 is 540 size and Castle 2200 is a 1/8 sized motor (largest) and I think would be considered a 640 size. With these large motors you usually don't see a can size, they just say "large scale" when describing the size.

The numbers are the rpm/volt. If you compare equal can sizes, the motor with the higher KV number will have higher rpm at the same voltage - that usually translates to more speed. But as kv goes up torque goes down, so there's a little trade off. Castle 5700 would be slower than a Castle 7700, but would have more torque.

Each of them are design for various application. Not sure if you are into buggy, truggy, 1/8 on road or crawler.