I run a Vamo V2 all day, got a 5v 510-threaded box as backup, and a few cigalikes for out-and-about or emergency situations. Also working on a 18650 mech mod right now. If I felt the need to get another backup, I'd find a US dealer with a Vamo V2 still in stock at a reasonable price and buy another. I'm a sucker for VW in my devices so the ProVari is automatically out, as are the eGo/Vision Twist/Spinner devices. With one minor exception, the Vamo V2 is built like a tank, and the only flaw I've discovered so far can be fixed for pennies in parts, and by not making the same mistake I did of over-tightening a cheap eGo/510 adapter down to it. Or just get a good 510/510 extender and leave it permanently installed if you don't mind a tiny gap between the body and your choice of topper.