Mike,
I am flying now a E6 with pyro 650-65 15T with 8S Gensace 3800mah 30C.
FLying very well for me.
This is with VBAR governance using hobbywing 120HV and hyperion sensor.
10S will give more power but should try to keep the weight down.
Mine is now around 4 to 4.1kg flying weight.
Jonathan