We just returned with my daughter, who was 18 months... she absolutely loved it... but, it depends on the child. My niece who is about the same age would never make it (just doesn't like to be contained, at all).
-Our daughter loved Pooh, Magic Carpets, etc... and Arielle's Grotto to "run around"... she also loved Mickey's toon town for the same reason. The key is to balance stroller, lines, rides and opportunities to run!
-We didn't do Buzz... we were afraid that the lights/noises might be too much (even though it's my favorite ride)

My wife and I did the ride swap for the "cool" rides (test track, Stitch, Mission Space, Dinosaur) and it was great.... You just ask the fast pass attendant for a ticket and then one person goes in the line (could be fast pass) and then when finished, the swap goes in the fast-pass line. Nice.
-Other parks do have baby care centers, and they are great.
-Although we were worried, our daughter napped in her stroller and it was just fine... this is usually when we swapped for the adult rides!
-Our daughter loved the character meal (Cape May Cafe), as well as park gatherings of characters... in fact, this was our favorite moment. She saw Pooh in MK and ran to him with arms open wide... she kept saying that she saw her "friends".
-The pack-n-plays in the resorts are just what you would bring from home, so don't bother... they even provide sheets (Mickey, of course!)
-We brought our big stroller (even on the plane) so that she could take naps... this turned out to be a great choice.
Initially, we were worried about bringing such a little one to Disney, but it turned out to be our best trip ever... again, if the children are pretty mild-mannered, it works... if they are a bit more high-maintenance, it may be a bit rough...
Have a great time!
