We are going to Sanaa on our next trip so I can't review it, but I would never skip Boma on a trip to Disney. It has the best variety of food for any eater, and our kids love it. They are adventurous too, but they have a good selection of 'plain' food if they aren't feeling adventurous on a given day. Almost everything there is not 'spicy' but flavourful (ie. you can still taste the food, not just the spices...).
Personally, I think you should do both based on what I have heard of Sanaa and my love of Boma...that's our plan anyway...