Millie's is in the parking lot of the Fairfield Inn - Mimi's is a half a block further north.
We have eaten at both places and recommend both. Millie's is like a Denny's when it comes to meals offered. Mimi's has a lot of home cooked type meals along with regular items.
IMO you can't go wrong with either one. Why not try both on your trip and you can decide for yourself?