I don't personally need any more power than what this istick makes. 12 watts with the Lemo at one ohm is plenty for me, but you know, YMMV.
The istick has become my daily carry to work/ anytime I leave the house mod. Gotta love not having to carry extra batteries everywhere I go and it fits in my t-shirt pocket way better than a full sized ProVari with an 18650 ever could. Charges fully from locked with the mini usb connection in 2 hours, no separate battery charger needed. I can charge it at work, or in the car using my phone charger that I already have.
Will it last forever, of course not, but at this price, I don't really care. Something better and cheaper will come out and I'll move on I'm sure, but for now I'm totally happy with it. I'm pretty confident that I could open it and replace the battery, I'm just no super gung- ho to try soldering tabs onto an 18650, but when this one dies I may try it just to see i I can get it done.
I got the Lemo because it is 23mm and looks good on a ProVari with a beauty ring, but on the istick it's still a great performer.
Lemo and an istick, about $75 all in.