I don't use ice but I don't have a bong. If I did I wouldn't use ice. I've smoked them with ice and the warm water shit. I'd go with warm/hot water. Reminds me of a steam room.
I use ice a lot of the time, I like it. When it starts melting, know what I do? Wait for it...I pour some of the water out. Though I love hot water bongin' too