I have used one, not too sure I am sold on it. I have the Ti version and yes its light weight. But, IMO their are many cons to this pot. If you are used to using a pot that has fins (i.e. jetboil) then you will find that you have a far longer boil time. My Primus pot with fins will boil two cups in like a 1:30 or somewhere their abouts. With this pot using the same stove it takes close to five minutes, this is with a Primus Omnilite running white gas. Funny thing is is that's pretty close to what an alcohol burner (Trangia) will boil the same amount in. Also, the threads on the lid are a pain in the ass, the lid sometimes gets hung up when trying to take it off, its easy to cross thread it. When this happens you feel like throwing it out the window. I find I am using more as a storage container and less as a cup or pot.
I personally think that it would be the perfect ultralight setup, but then you would have also go to a ultralight stove setup. My stove setup is not ultralight and I do not plan changing my stove setup. If you would like to try one PM your address and I will send you mine to try out.