Got a hitec951 servo and upped the voltage on the esc to 7.4. Plus a set of the badlands to compare to the much bigger six packs. For race days at the backyard track I'll probably use the badlands, for bashing the six packs... We'll see. (Note: make sure servo and receiver like 7.4v before changing on esc- as if I need to tell you guys!) Also, I got what I think is a faulty 4S from trakpower. Cell 1 plunges below 3.0v by the time the others hit about 3.3. Happened both times I used the battery. Trakpower is willing to replace but I was going to run it one last time before cutting the leads and taking a pic as they require for replacing it.