There are some excellent bodhran players - Ciaran Boyle springs immediately to mind, as does Will Lang.

If someone's good at it, it adds a great deal to the music, like any other instrument.

But I was at a session a while back where people got a bit excitable, and there was a djembe, a sort of drum you play with sticks, someone playing the spoons, and the bodhran player decided his drum wasn't loud enough, so turned it on it's side and started battering on the rim. I couldn't hear whatever tune it was me and the fiddler were trying to play - it just sounded to me like I was in a wheelie bin that six big lads were hitting with cricket bats.

This made it a bit difficult to play, but I didn't really mind. Everyone was having a good time, and that's the whole point of the session, I think.