I've fed the Cowboy Cookout - recommended as the closest to a mouse diet.
When I first started feeding it, Buddy loved it. Then when I purchased a new case the consistency changed from being soupy to more of a Pâté, and he lost interest.
I was looking for a grain-free food, and the Merrick's Cowboy Cookout fit that preference. But the meat is beef, and I read that beef isn't as digestible as poultry (?).
As far as not eating all the food served - this seems to be commonplace in my experience. Even cutting back on portions doesn't work, they still seem to leave a little something behind - I think they're just trying to follow some cultural edicate that believes it's polite to leave some food in your plate when you're finished eating.

(
http://www.tripadvisor.com/Travel-g1...Manners.html):)
Right now I'm trying out Weruva - the chicken recipe - has a lot of gravy and is very popular with all the cats.
http://www.petflow.com/product/weruv...anned-cat-food