The duration of the flight is proportional to the TYPE of flying done.
My 12S Freya can:
-hover+easy Fwd flight for 12 minutes (1600rpm)
-fly combination 5.5min hover + 4min of fast aerobatics (1550/2050rpm)
-6.5 minutes of balls out fast aerobatics.
All based on 80% of my 5000ma packs.
Even after toning down my collective I still have way more power than I ever had with nitro. You just learn how to be responsible, or stuff will break! Another benefit is that well setup electrics are really smooth.
Big power costs big money, but it will put a smile in your face.I fly electrics strickly for competition. I kept my nitros for the other fun stuff.Unless you are sick of nitro helis, or really have the need for 1000hp on tap, stay with your nitro helis.
The end goal is to have fun.