The Wilson is easier to drive and the tweeters are more polite than the Opus Ceramique's. That's based on my experience having owned Eidolons for 11+ years and listened to both Opus Ceramique and Wilson WP7s. WP7s do not sound like WP5s and WP6s. They are actually extremely buttoned down and can work well in small rooms.
The Opus Ceramique will not give you any possible bass problems with woofers overwhelming the room but don't expect the highs to be as detailed and refined as the WP7.
The Opus Ceramique will not give you any possible bass problems with woofers overwhelming the room but don't expect the highs to be as detailed and refined as the WP7.