We go each year, and love Chef Mickey's. The characters are wonderful, and the kids love the singing and napkin waving. (If you are looking for a nice quiet meal, this should NOT be your first choice!)
That being said, we have also seen a steady decline in the food quality over our last 3 visits. I think someone needs to wrap up this thread and send if off to Disney! I don't see anyone saying how the food has improved, so I don't think this is just a 'timing' issue.
At $23.99 an adult for a buffet, I think Disney needs to bump up the quality as well. But, since it is always full, I guess they figure they can raise prices and lessen quality until is starts to effect attendance. Sigh.
Now, as a few others have pointed out, the 1900 Park Fare Dinner buffet was WONDERFUL. We could not get over how good the food was - and the Pooh Characters were a lot of fun as well!
We're going back to Chef Mickey's in December for another try. (So it isn't so bad we won't go back - yet!)

If you have a reservation, I think you will still have a good time!