Remember they may or may not like the characters. DS23mo loved the fuzzy characters, but the 'face' ones were unnerving for him(the ones that looked like real people). It was like he didnt mind hugging a giant stuffed animal, but the ones that looked like strangers were intimidating.
So we did CRT, but he didnt really enjoy it (but I did like starting our morning early in the MK).
We also did Chef Mickeys and Crystal Palace. We preferred CM, but had a great experience at CP too. I would say, if you have some time NOT in the parks (at night after AK closes, or your arrival evening, etc) CM was awesome and totally worth it. If you dont have a lot of park time, just stick with CP on a day you plan on doing MK, that way you dont have to leave the parks.
Definitely make some ressies at the 180 day mark, then if you need to try to change them later you can try, but you will not be stuck without a character meal.