We eat dinner at Chef Mickey's on the first night of every trip. Although the food is not "gourmet", we enjoy it very much. If you expect high quality food, you will be disappointed. If you expect normal buffet food, you will be fine. I know the price is high for "just ok" food, but it's Disney and it's a character meal. I think you are paying for the entertainment value.
Chef Mickey's is one of those places that just has the Disney spirit. Being in the CR, with the monorail going past, the festivities of Chef Mickey's....I don't know, it just feels right to us.
The dessert bar is very good, btw, and as far as seating is concerned, we have never minded where we were seated. I just don't get "bent" over stuff like that!
My opinion is you have to form your own opinion. Give it a try, and if you dislike it, you don't have to go back! You may find that regardless of what others say, you will like it and make it a tradition like we have!