My MVP2 is still a stand-by for my nautilus mini. Long battery life is great, I can go a full week without needing to charge my MVP2. (I usually use other devices/RDA's, the MVP is just convenient when I'm in bed or in a rush).
Might be worth looking into getting an rDNA? The price point is a bit higher, but it'll perform (if not outperform) the MVP2. It'll also allow the possibility to go to rebuildables, because the MVP2 really doesn't perform well with an RDA.
It's up to you. There's also the eleaf Istick. Or if you wanted a super-long battery life, I'd say get the IPV3 and use it around its lowest wattage setting (7W). My IPV3 at 11W has lasted 2 weeks so far, with a 1.8 ohm nautilus in it.