I never saw Cirque de la Mer, so I can't compare (hey, I rhymed!)
We did see Odyssea and both of my daughters (5 and 7) as well as I enjoyed it. We thought it was beautiful. We do enjoy acrobatic, gymnastic exhibitions, and also marveled at the flexibility of the performers. It was not one of our top three attractions at Seaworld, but definitely worth the chance to sit and rest in the air conditioning and be entertained at the same time!