Cant comment on rythmik as I have never heard one b4 but their service is not as good as others.So you've never heard one, but you know their service is not as good as others? Might I ask what you're basing that on?
I own three Rythmik subs and have never had one break, so I can't speak to their service, but anytime I've ever had a question they've been responsive and helpful. I don't know if they still do this, but they also let me transfer the warranty when I bought my first one from the original owner.