I agree completely. Kids love 'em. I think they are a challenge to exhibit well: the Slimbridge exhibit is the best I have seen, but I think it could be bettered.
I have always thought that Chester should have a world-class harvest mouse display, as they have a breeding programme for restocking the local area.
If you have a very long glass exhibit they should work, just have to be careful as they have a habit of just dying or killing each other, not an easy small mammal to keep.