Turnigy nano-tech batteries

I haven't had good experience with Nano-techs, which is weird, since the normal Turnigy packs have served me well.

Got three 4s 25-50c packs, all three are light puffed and can't hold voltage. To start with I would get 14 minutes in my 8ight, but last race they all tripped the LVC after 2-4 minutes. I ended up borrowing a pack, a Turnigy 4s 25C 4000, and that had no problem giving me the 10 minutes I needed.

So know I'm kinda on the fence on what to go for, for next year.