I have had one for years and smoke out of it every day. My two favorite things are:
1) if it tips over it wont spill (unless it tips forward, some will leak from the stem)
2)I keep my lighter in the top where your mouth goes (the first bend keeps it from going down)
I cant tell you how many times people are holding the bong and looking everywhere for the lighter that was just going around with it. I have also accidentally dropped a lighter down my friends straight tube on accident. Damn stoner....lol