The importance of finishing is not to be underestimated.
Like refactoring code or editing a piece of writing, it's those later steps to really clean things up that make or break a drawing or painting. Even as an artist, this is a fact that's hard to keep in perspective when you see a really impressive piece of work from someone else. It's easy to think it just sprang from their tablet/pencil/brush fully formed, when it probably started just as rough as any other sketch, but was refined over time...
Anyway, I don't mean to preach. Point is you can't really judge the finished work based on early sketches, which is part of what made comparing the different studios so hard. Heavy Cat did things a little different, and sent really loose concepts, which allowed them to be very agile in responding to feedback and tuning the style to match the project. The other studios did much more polished, impressive work, but that's because they (more or less) jumped straight into final art mode. It seems like they sort of specialized in one style, too, whereas HC tries to embrace a range of tones and styles.
My biggest concern remains HC's character art. Not because it isn't solid, but because it is so different from AVWW's current art, which I actually really like. I hope they can capture the sort of realistic, naturally proportioned simplicity of the pre-2.0 art... I'm quite confident, they seem to be very hard working and dedicated.
Looking through their portfolio, I think AVWW just needs backgrounds done by whoever did the series of fantasy landscapes. O.o Holy crap those are good.