don't know if this addresses what you are asking but i remember having lobster on the second formal night in one of the anytime restaurants... don't need to go to the specialty place to get that.
never paid for the ice cream at the parlor... just ate it with lunch/dinner... don't think that the free ice cream is as good of quality (texture, richness) but the flavors were more fun. i had some white chocolate ice cream that was pretty yummy.
don't have a means for comparison (only been on the one cruise... so far) but found the food on princess to be good but not memorable. the one thing i really loved and look forward to eating again was a crab quiche appetizer that was an option on one of the formal nights... that was veeerry delicious! and my fiance still has dreams of some crazy chocolate dessert he had... doesn't remember what it was called just remembers it as the "choco-gasm" lol!