I asked that question a while ago and although the majority ppl responses were not worth it. We went for it at the end because of the priority booking to the specialty dining and the little nice to have perks like access to the spa (though u can pay $25/person/day), room service with access to the menu in GDR (but ppl said they would bring u everything in one go and there is not a table big enough to put down everything), free laundry x 3 (you can still do your own in the ship), free bottle of champagne (u will also find champagne during your meals), concerige lounge (it is not a big one)
But it was only $150 difference/pax for us so we might as well try it out as it will be our first time on O. Let's see.