I love my Turnigy Nano-Tech batteries. It's all I use, these days. You can get them from Hobby King. Price is about the same as Gens-Ace. But I use them in my cars, my planes and my quad copters. I have about 30 of them all together and every one of them has been excellent.
http://www.hobbyking.com/hobbyking/s...arehouse_.html