Yes, but real world setting, do you think under load it is really seeing that kind of rpm? The voltage in the battery will drop as soon as you go. Perhaps if you were geared down it would run at high rpm, but in my case of doing all out speed runs, it takes some time to get it at high speeds and I don't think I've been able to top it out due to the car being too far away to want to keep going that fast. I'm starting to believe that without a ubec, the temps of the esc will get too hot too fast. The 5700 probably pulls less amps than the 6900 and if you combine that with higher voltage, the 6900 will probably put the esc at unsafe operating temperatures whereas the 5700 won't and keeps it within its recommended range.