I never could tell the difference a battery could make until I got into mech mods. Some have higher internal resistances, but really, on a regulated device, it doesn't make that much of a difference. I had an AW 2000mah 18650 and in my SVD I cant tell the difference between that and a VTC5 or and Efest 35 amp. The best battery for regulated devices is the battery with the highest capacity. If you are really interested in how batteries can affect performance, there is a chart on one of those other forums that a man by the name of JKuro made. It compares internal resistances of some of the most widely used batteries. If you don't really care, just stick with sony and you will be fine. Those are some damn good batteries.