Supergo is part of a national chain, so they have the advantage of pretty good selection and prices. This store also has a large selection of bikes ranging from commuters and cruisers through higher end road and mountain bikes.
In my visits, there were a few knowlegdgeable, experienced salespeople, but also several that didn't seem to know a lot. I guess with a big shop they have more staff in general, and you get a few more new guys.
I bought a Specialized mountain bike from them, and was fairly happy with the experience, but not so thrilled that I'll necessarily go back again.
They have a store brand of road bikes called Scattante that are reasonably priced and that I have heard good things about.