The only way I can imagine a tank being low quality if with the valve. When I first started playing the 9oz that came with my tippmann's valve wouldn't seat on its own so I had to use pliers close the valve all the way after playing. No amount of oil helped and I even got the tank replaced. Really it wasn't a big deal. If you get a tank with a moot valve you can just get a used replacement for cheap and put it on the tank body. As long as it meets safety standards it should be fine. I prefer the long skinny tanks, the stubbies are good for smaller people though.