from what ive read it seems the lower the kv the better? i used to use a kk board but i found the multiwii boards iare far more stable, especially when in stable mode (would you believe!). plus you get a nice gui to program them with which is nice

i have heard of issues with the esc update speed being too slow and making it to slow to react to small changes but not of your problem sorry. maybe your gyros need reversing or something? i do remember messing about with my kk board for quite a while before i got it to work right.

my hex has a 4000ma 40c battery and it seems to last about half hour not sure about my quad ive only flown it briefly before the wind got the better of me. when i get home tomorrow ill get some photos of stuff for you.