I've been considering picking one of these up for a while, they look nice.
my two hangups:
steel tank, can't see the juice level, I'm spoiled and have not ever used anything that didnt allow me to see my juice.
18350 bat's, don't own any dont want any really, I go through two+ 18650 a day I don't want to change batteries that much.
The sidewinder is the only mod I've seen that makes me consider overlooking these though, and I'll probably pick one up some day.