we regularly eat dinner at hollywood & vine because it doesn't use the characters then. i'm not a huge fan of character dining (without kids in the party). i am a VERY picky eater and i find this buffet to offer a lot of variety for all taste buds! & the kids bar has all the standards - mac & cheese, chicken nuggets, etc
it's been a few years since i had dinner at crystal palace (2004) but i remember the food to be a little less fancy then H&V and more kid-oriented, overall. but i also remember that we really enjoyed the overall experience - table service at MK is always a good thing!
i've not had the pleasure personally, but i've heard nothing but good things about the princess storybook breakfast. i also agree with the others who mentioned a break from character dining...i can see how it would be distracting for the kids and it's a little disorienting for the adults too! there's constant activity around your table at a time when you're supposed to be enjoying a meal....pros & cons, as with anything!
ps - another fave is the best friends breakfast at the polynesian. the food is wonderful and it's a great way to start a day at MK!