I find the most important thing in a pipe or bong bowl to be the actual shape of the bowl itself.

often times, you will come across a mass-produced metal or glass bowl shaped like this \ /
the problem being, air is pulled in from the sides rather than straight down and the weed on the bottom is burned unevenly as a result.

I prefer bowls shaped in this fashion: U. steep sides, and deep. this way, air is being pulled directly down from the top making it easier to cherry the bowl.

I usually compare bowl width and depth using my pinky finger. stick your pinky into the bowl, then the next, then the next and see which bowl harnesses your pinky the most comfortably :thumbsup: