Overall it's useful in the sense that you can put it on larger water bottles (does not fit on regular sized poland spring bottles) and it's extremely portable. The glass stem will get extremely dirty rather quick though so you'll have to clean it out. I've also noticed while pulling, its efficient like a normal bong at accumulating smoke, however when it comes to removing the stem (I found that it works better to partially remove the stem rather than fully taking it out), you need to inhale hard enough for the bottle to collapse on itself. Overall; easy to carry around, needs to be cleaned sorta often, and needs a little time to tinker and play with to figure out how to pull in the most effiencent manner. If you're smoking at home, I'd recommend spending just a little more on a piece.