I agree that the Istick is a great device. The only thing I do not like about the istick is that it fires a little hotter than what you actually have it set for. I tested it against my provari, MVP2, and VTR. Obviously, all you have to do is set it to taste and not worry about the number... but for some reason, I just had an issue with that.
Also, take the size into account. I have big hands, and although the MVP is not extremely bigger than the iStick, it is still bigger... and heavier. That is what I prefer.
Now... about the MVP, you need to know that it has to be relatively the hardest button to push on any regulated mod I have ever tried! But again, it is all relative. I have no issues pushing it, and I like the bulk that my thumb muscle has developed. So much so that I am considering a career in professional thumb wrestling.
All said... you cannot go wrong with the either, but my preference is an MVP. I never go over 9 watts with a 1.2-1.5 coil in a Kayfun. The battery never fails me, and it could actually be used as a weapon, if a situation ever arose! It is a sturdy little box beast.
Lastly... I suggest investing in a Kayfun type atomizer tank right away. You have to learn to build coils, but it will take all of one day to learn. I have been through boge cartos, clearomizers, protanks, rebuilt protanks, nautilus mini (which is fantastic by the way with that vertical coil), etc. I only wish I had started with a Kayfun. It will save you money and I have not had a better vape. I have no interest in sub ohming, so it works perfectly for me.
Just MY opinion! (Dime a dozen).