I had a 35' Ionics carbon pole for a while but the clamps gave up clamping and I couldn't carry on with it.
I used it tops and bottoms for ages, no wonder I look like Mr Universe.
Anyway, I went and got a 18' glass and I think it's great... BUT, it's a bit whippy/bendy, and am I bit othered about getting a bigger one if it's goning to be really bendy.
I can't see needing a pole beyond 21' feet really.