Beyond the basic fee and whatever gratuity you choose to leave, it is totally up to you as to what your total cost will be. At brunch, you get a glass of champagne/mimosa as a part of the brunch, so unless you're looking to "biggie size" your alcohol intake at Palo brunch, it works out to be pretty reasonable. As for service, we were assigned the same server with whom we had established a very good relationship at dinner a couple of nights earlier, so he was very attentive to what we had on the table, making recommendations, ordering a couple of things in advance for us to try (knowing we were coming in), getting recipes for us, and just generally making our meal time very pleasant and enjoyable, so we were happy to tip him pretty well.
As for serving yourself or having them prepare your plate, that didn't really bother us. On our April cruise on the Fantasy, there was a bug/virus going around, so even the ice cream machines up by the pool stopped being self-service, so we were not surprised when the Palo brunch line was also served to us. Definitely makes you think about what you really want when you're asking someone else to get it for you, and frankly, that probably saves them a few dollars and me a few pounds...although, again, our primary server was very generous in his willingness to get us various "made to order" items "just to try", that adding a few pounds was not a particular challenge!
I would argue that Palo brunch is probably one of the better deals on the ship.
