I'm in no way suggesting the iStick

I'm a big fan ov the MVP2 if it has the power you are looking for. Given the small cost and space added by the USB output, I'm shocked more devices don't offer that... it was a huge reason I picked the MVP2 over other devices.
I'll likely pick up the 20W device after I see a few people confirm it's just as good as the MVP2, but the reality is that I use a DNA/Hana type box most of the time if I'm not using a mech. But I even bought a couple MVP2's as gifts for other people that I got started in vaping and they still love it and haven't moved on to any thing else.