I have had one of these, the v2 that I got from LitecigUSA, since Christmas. I use it on a daily basis, not all day long because I'm usually near a pc and use a PT, at least a few hours a day. The battery lasts me about 5-6 hours and I rarely stop
vaping.
I know some people had problems with the v1 and others have problems with the design in general being a knockoff.
But to me it is definitely a good sturdy little
device and works perfectly every time. It is a good idea to turn off the bottom switch before setting it down and walking away from it, or even taking the battery out if you're leaving it for an extended period of time, as it does have a cleaning cycle that is an automatic process and does get quite warm during it.
The 901 does run well on it. I haven't yet tried the 510 on it but do have adapters on the way.