RE: Himax 2015 4100 or 5400?
I run a 2015-4100, 6.6-1 gbx, CC25, GWS 12x6, TP 1320 3S, in 16oz foamy. I have alot of time on my motor, no problems. The motor does get warm, but you can stand to hold onto it. I have also ran 10x4.7, 11x4.7 & 11x8 props, just depends on the how much weight I'm flying with, and how much punch I want.
I think the the higher KV motor would need either a 2 cell pack or smaller prop, or it would be to high of amps, and get hot etc: damage the motor.