I've had my ProVari for over a year, and really love it.
I did, however, get myself a box mod for when I'm out and about. I just found the ProVari, with a Lava Tank, a little bit too tall to carry in my shirt pocket, and I'm not going to chance putting a ProVari with a Lava Tank in my pants!
I ordered mine with the extension, but seldom use it. The ProVari is already pretty tall, esp. with a tank on top. Add the extension, and now it's really tall!
Battery life with the 18500's are not bad at all. Get the AW's. Unless you leave the house at 7am, and don't return until about 10pm, you should be able to get through the entire day. Even if you can't, it's easier to simply carry around a spare 18500 then add the extension to the PV, and have to deal with the extra size!
My