RE: When to replace Lipo's??
I can't speak to the Align packs, but the DN (get 20C) packs are pretty nice, I've flown about 5 times on each. I'm not into much heavy aerobatics - just hovering and forward flight, some inverted) however I honestly can't tell a difference between the DN 2 pack special and the $80 Thunder Power eXtreme battery.