I did use the small gear quite a bit on my Trek for the hills in my area and I feel as if I am missing my "middle range gear" on the Specialized (I am guessing this is the 16)?

How many mm's of space do you all keep between your wheel and the brake pad? Mine were so close initially, that I really had to look to make sure they weren't rubbing. I just loosened them to the point that I can see the space between the two, but the brakes still do their job.

Would you all wait a few weeks and get a fit before you switched out the cassette?