I waited for a lull in flowering, after the winter flush, and cut mine back. I pulled out the straggly pieces which were making mine untidy, then cut them off. It looks a lot better now, and has produced flowers too. I didn't cut it hard back though - just to tidy it.

You and I agree SH - except mine has never actually finished flowering. I just tidy up the dead-looking bits as I walk past it and turn some of the longer strands inwards.