In practical terms, one great advantage of the Sonettos is their down-firing bass port, which makes positioning in a smaller room wonderfully easy. I have mine less than two feet from the rear wall and find they "sing" quite superbly without any fuzziness or over-loading in the bass department.
I have no doubt that the Olympica Novas probably sound even better, but I'm actually happy to forgo that advance for the convenience of being able to move my prodigious bulk around my living room without mishap.