I have about 25 6600 and 6000 batteries. Buy at least the 6000 batteries, they are same size as 5300 and get longer run times. Out of the 25 batteries I have only had a couple puff. Puffing is cause by many things, and its not the batteries problem. They don't puff enough to be unusable, and they work just fine after they puff. Considering it would cost me at least $150 to get the same battery as a $50 hobby king. I'll gladly take a few puffed batteries. I use the 65c-130c batteries.

Btw with 2 6600 nanotechs I get over 25 minute run time on my 1/8 scale. I have yet to have a main i couldn't have full power through the entire thing.