I bought the istick 30 watt for $5 more than the price they were asking for the 20 watt. I'm only using it at 12.5 watts now, but it's good to know that If I ever want to, the 30 watt can sub ohm, where the 20 watt couldn't.
As for the MVP, some people don't like how hard the fire button is to press. I like my MVP. Sometimes when just holding my istick, I accidentally press the button without intending to.