They're functional and usually better looking than the default interface, but that's a pretty low bar. I still wouldn't classify them as looking "good".

I haven't tried Tomato but I do use OpenWRT. I don't have anything particularly good to say about its web interface.

Ugly. Not intuitive unless you are an expert. I wouldn't expect someone's grandmother to be success using it; constraining that with the airport setup that is super simple.