I'm going to be in a very small minority that is going to say it wasn't worth it. Or scratch that, it's worth it to try once. I did both the dinner and brunch on my Alaskan cruise and while both meals were very good, they didn't blow me away like I expected. I guess my expectations were incredibly high after reading all the rave reviews on this board, but I didn't find the dinner any better than the MDR meals. The brunch was very good and I enjoyed experimenting, but I was pretty full pretty quickly and didn't stay nearly as long as others seem to. There was nothing I just had to go back for seconds for, and the grape pizza everyone touts on here, while different and tasty, just didn't blow me away.
I'd say Palo is great to experience once, but I won't be going out of my way to book either the dinner or the brunch again. I think if I were traveling with friends or others who want to try it, I'd talk them out of the dinner but agree to do brunch again.
It's really only great for couples with children to escape the children, I think that's the real appeal.