I'm currently on the Minimed 522. I tried the OmniPod sample at a JDRF Walk last year, but I didn't really like it. I wore it on my arm, and it was quite bulky and awkward to wear.
The tubing on my MiniMed gets on my nerves, but I much prefer being able to disconnect at any time over having that bulky OmniPod glued to me 24/7.
When the OmniPod gets smaller (and more reliable), I would happily switch. But right now I don't think the technology is strong enough.
On a side note, have you considered disconnecting from your pump while you dance? I'm not sure how long per day you dance, but you can stay disconnected for up to 1 hour at a time. (Then just adjust when you reconnect) That would solve your problem!
I take several hour-long workout dance classes (cardio hip hop, etc.) and just make sure i'm at a good level (for me, about 125) before the class, disconnect, and dance my heart out! I usually have it off for about 1 hour 15 minutes at a time, and I really don't notice any huge spikes or lows in my control because of it.