One word: amazing. My Prodigy arrived today. The 801 atomizers I had on hand are a perfect snug fit. The end cap required hubby's assistance to completely attach...nothing major...according to him: "you're just a girl." ; P I imagine the spring will give in time...or it would be easy enough to adjust if necessary. I'm using an 801 atomizer, with a 901 adapter on order. While I'm only able to compare it to an 801 penstyle, a 901 mini, and a few misc. disposable e-cigs, I believe I have located my permanent vaping apparatus. I will have to adjust my draw...as it produces such an extreme amount of vapor that I coughed for a bit. You can hear the juice sizzle when you depress the button...and a very slight draw is all it requires (for me, anyway). I am pleasantly surprised to discover that I didn't notice a flavor loss with the 801...which I was concerned about. The atomizer runs a bit warmer...which I expected. This may consume a bit more liquid...but I'm fine with that...when considering the increase in vapor production. Four months and several hundred dollars later...this is what I've been looking for. Initially, I wanted something that had the look/feel of a "real" cigarette. Now, I simply want something that I'm not constantly charging/changing batteries/struggling with it to get good flavor/vapor. This is it!