You will be seeing different characters. Of couse you will be seeing princesses at Norway, Crystal Palace is Pooh, Piglet, Tigger and Eeyore, Chef Mickey's is Mickey, Minnie, Donald, Pluto and Goofy. I haven't been to Tusker house, but when it was Donald's Breakfastauraus, there was Donald, Mickey, Pluto and Goofy in Safari outfits. If you don't want Mickey and Donald again, you could try O'hana's with Lilo and Stitch. We did that one 2 years in a row. Very good!
I would suggest in doing them all, but that is just me. We love the character buffets for either breakfast or dinner. They character interaction is always good as a good variety of foods for my picky family to choose from.