The assumption here is that you are flying 8S. Is that right? Personally, I like 5000 mah with an 8S power system. In the old days I flew TP 8S3P 6000 mah batteries. I once lost a plane due to running out of battery before I could land so I always like hauling a few extra electrons aloft... just in case.

That said, on my Reactor I fly 6S 4000 pack. If you go up in voltage, you can create the same wattage with fewer amps thereby allowing you to use a lower capacity battery. This is a big part of what made electric power so much more viable than it was back when we ran NiMh or Nicad. We could run higher voltage without making our planes weigh a ton.