In reply to Clinger:
For best rubber it's between 5.10, Evolv and Mad Rock in my opinion. Each one fits differently, though - so pick on that fits your foot best! Often it's the shape of the shoe as well as the rubber.
If you're looking for edging skill and accuracy improvement worry about the style, not the rubber.
Go into a good climbing shop in your area and ask the questions with the boots right there to try.