hobbywing esc in a e-revo

[jsr]

Yup, you'd be faster than the revo 2.5 if you use LiPos. LiPos have lower internal resistance and can discharge more current. Brushless motors need a lot of current when accelerating. The ease of current supply from the LiPos allows for more "punch" as what's_nitro put it, better acceleration, and depending on your BL setup, more top speed. The more aggressive the BL setup, the more LiPos will make a difference on top speed as more speed mean more current. Even the best NiMHs can only deliver 40-50A. Even low-end LiPos can deliver that much current.

Also, LiPos will tend to run cooler and longer under the same setup (ESC, motor, gearing, etc.).