I happen to have two and I like them both and have found the "external charging" capability to be quite handy. For example yesterday while waiting at the VA hospital (12 hours, grrrrr) my phone had died so I set it in the car to charge. Unfortunately for some reason my phone (windows nokia phone) does not seem to get enough power from the car charger to get it going again (It sat for 2 hours in the car, lit up but never charged even enough to power on). So I took it out of the car and hooked it up to my MVP. Lo and behold it fired right up and started charging properly. So the charging feature has helped me at least, not to mention lying in bed at night charging my iPad while happily vaping away (I read somewhere that the MVP could not charge an iPad which I have found to be false information as mine charged fine).
On another note, I chain-vape constantly and the mvp has lasted me roughly two and a half days without needing a recharge. It was the first mod I purchased and so far I have been happy with it, for the price you can't go wrong. Vision tanks pair up well with it along with Kanger tanks with a 510-to-Ego adaptor. And paired up with a shorty carto and it gives a very nice vape. If this is your first step up I would recommend it, especially to a new user who wants to see what all the fuss is over a VV device. The only thing I can think of off the top of my head that I could want (besides VW) is an atomizer ohm checker. I hope this helped some
