I just got my mvp in the mail like an hour ago, and am very pleased! It fits all the tanks I have tried so far(t3s, evod, vivi nova) perfectly. Before this I used a couple of different spinner batteries that worked good enough but this is much nicer. Also the power cutoff isnt an issue since the mvp will go for 10 seconds. I was worried about it feeling awkward since it is a box, but it feels totally natural. Can hit the button holding both way without any issues, index finger or thumb.
I cant speak on the svd, but if you go with the mvp I think you would be very happy with it.
Picked mine up on ebay for $45, got it 3 days later.
Another cool thing with the mvp is that you can buy all sorts of wraps for it if you wanted a different color, or if it gets scuffed up later on down the road.