I've eaten at both places, several times. Spoodles use to be a must-do for us, but the last two times the food was HORRIBLE. Portions, freshness, taste--you-name-it--something has gone wrong with their menu and whole approach, at least as of last July, anyway. We are generally not complainers, but two people in our party of 12 sent dinner back last time--it was inedible. This is the only time I can remember our group sending back a meal at Disney.
Boma is still a family favorite--but, as two other posters pointed out, this is not an American-centered-palate kind of place. There are lots of different spices and types of food on a pretty decent size buffet. I like the opportunity to sample recipes that I don't normally get at home.
Mine and my sister's kids like Boma, and there are some "comfort foods" for them, but they also try the other offerings. Boma desserts are fabulous, as with all of the Disney buffets, and include some American favorites.
So, I think Boma is a good choice, and unless they've "fixed" Spoodles recently, I will stay clear of that restaurant.