I use my Gravity Bong 24/7 if its just me. I have a little .1 gram bowl that I use with it, which is just the right size to get me blazed, and two bowls from it has me wrecked. It saves so much weed.

And personally, a normal bong tears through weed way too fast. Id use my pipe before Id use any of my bongs if I was trying to save weed.