I have the Prodigy V3 from Puresmoker, and I have both the 6v setup (two 3v LifeP04 batts) and the 3.7v setup (one AW 17670 batt). I run a standard resistance carto when vaping at 6v, and a low resistance carto at 3.7. To me, the difference between 6v and 3.7v is night and day. At 6v I get a very warm, flavorful vape, great vapor, great throat hit. At 3.7v, not so much. And it's all because of the voltage difference, pure and simple. At 3.7v, it seems like I can vape and vape and never get "full." The satisfaction just isn't there like it is at 6v. Those that have never vaped higher than 3.7v don't know the difference, but once you've vaped at 5 or 6v, it's hard to go back to 3.7v. At least that's been my experience...