+1 for the provari. You can get the 2.5 with the 18650 extension for about 120 now and the build quality is phenomenal. I use that when i'm at home and not dripping. I know they are considered underpowered now and maybe just "hyped" but man oh man they just feel supremely well constructed.
I have a couple of the sigelei minis (30w) that were 33 bucks each and i use those when i'm out and about / on the road. Not sure if they will last for years, but cheap, have been good for a few months.. And i figure even if they died quickly i could still use the batteries with something else.
I got 2 istick 30s early on, the mistake was paying double at a b&m. One is still ok, though i never liked the feel of the button. The other got extremely hot using it at 29w, that scared me a bit so i dumped it. Given everything i've heard about lipro batteries i didn't want to risk keeping using it if the battery had already been stressed. The other thing that was true for both, the power adaptor for charging got crazy hot too, which didn't give me a lot of confidence.
May be just silly after all my mac laptop can get scaldingly hot on occassion too, i just have more faith in the technology in that.