The problem here is that good UX isn't borne of qualitative analysis -- you have to build something worth analyzing to begin with.

Once you do start analyzing, what do you do with the results? You can try to make small tweaks -- it can be worthwhile if what you have is already good. If what you have is bad however, no amount of rigorous analysis is going to solve the artistic problem of coming up with a cohesive vision of something better.