It's awesome. I love mine. I started with ego twist and a vision spinner. (pretty much same thing). My ego was a 900 mah and spinner was 1300 if I remember correctly. Was always having to have one charging or charged. The 900 would last about half a day. The 1300 would almost last all day.
Upgraded to the MVP 2.0 and the battery lasts me now 2-2/12 days and I vape heavily so it's used constantly. Biggest factor for me. Still have my ego as a backup when the MVP needs a charge. It seems like it'll take almost 5 hours to charge, but I let the battery drain all the way.
So, biggest factor for me was the battery life, which is awesome. Yes, as others have posted, I notice better flavor too. I use tanks (mainly iclear 16's) and do have a kanger aerotank. This was my first (and only) VW battery and I do like it. Most of the time I keep it on 8W. There area a few juices I like a little hotter, but 8 seems to be good for me. That's just me and I know everyone is different not to mention juices are different too. Since I mainly vape fruit flavored juices that's a good setting because too much warmer and they get that burnt taste.
The usb charger is a neat gimmick, but I've never used it. I suppose in a pinch it would be nice but who wants to rob precious battery life when you could be vaping lol. The built in ohm meter and other settings are nice features too. It does have a hit counter, but to me that's just a feature that is neat, but seldom used. I don't care how many puffs I've taken, although I am surprised sometimes on how many

.
Since the egos don't have a counter I don't know how many hits I was getting before the battery needed a charge. I do know on the MVP I can get 1200-1300 usually before a charge, but again a lot of that is going to be relative based on how long you hold the button when you vape, how many ohms you're atomizer etc. is; your voltage/wattage setting, etc.
I paid $50 for mine at my local B&M. It came with 2 iclear 16s, a beauty ring and charger. Considering the tanks are $5-$6 that's a battery for under $40. Awesome price for the battery.
I have no regrets, and if anything happened to it I'd buy another in a heartbeat. It does max out at 11W which for me is more than enough. I don't ever vape that high.