I started with the Inferno and had only one problem with it - that the battery didn't work if it got too cold, as in sitting in the car all Winter night. But overall I was very happy with it and it got me off the cigs virtually overnight, except for that first morning cig I had for the next 6 days until the open pack was gone.
The proprietary battery can easily be counteracted with a simple adapter that shouldn't cost you more than a few bucks.
Volcano also has an excellent warranty. If you find any problem with it at all, they give you a no hassle replacement. I don't know what Joyetech's warranty, if any, is like. And I also have no personal experience with their batteries, just a couple of their atomizers, which are good.
However, I might have gone with the Joyetech if I had done more research. I think they might be a bit cheaper and are still highly regarded among vapers. Maybe if I find myself with some extra money one day, I'll get one just to have it in my collection or if I need a smaller unit for something.