Hi there, Carter!
Like everything, restaurant preference is quite subjective. Third party sites like www.AllEars.net provide hundreds of user reviews of restaurants all over Walt Disney World, and you can get a good sense of what people in your travel situation think of
Chef Mickey's.
The food is fine. It's actually pretty good. But yes, it's a buffet, so small eaters might feel that they aren't getting value for the dollar. Alternately, lots of people opt to do a late breakfast/early lunch and save the dinner for the mail meal. Again, a matter of personal discretion.
In addition to being a buffet, it's a character buffet. The Fab Five - Mickey, Minnie, Donald. Goofy, Pluto - circulate throughout the room, greeting people, posing for photos, and signing autographs. While this appeals to a wide variety of Disney fans, it definitely skews younger. Chef Mickeys, even at 8:55 PM, is not going to be a quiet, reserved place. If you and your dining partner are comfortable with some "spirit" while you indulge, then you ought to be fine, but if you're looking for a more adult-oriented or traditional atmosphere, Chef Mickey's is likely not going to be a good fit.
While I would not presume to make the decision for you, I would encourage you to consider the pros and cons of a late character buffet meal. Reviews should be simply a starting point as you proceed through your planning process.
If I can be of any further assistance (including suggesting different types of dining), please stop back by!
See you later, celebrator,
-Deborah B.