My question is about efficientcy. If the setup will run more efficient on higher voltage (cooler temps), there is no reason not to. It will only go as fast as I pull the trigger. Which means that any stripped gears are due to too much throttle. As Ryan would say, "No such thing as over-powered"
Leaning with 6s now, but would like to get a few more opinions first. To be honest, I wouldn't mind more runtime. Temps are the only issue. If I am not able to run through 7k plus on 4s without going into thermal, no reason IMO.