Thanks to all for the input. Went to my LBS today, got fit tested and road 4 bikes. The 58cm was good in terms of leg extension and "roominess" but I felt somewhat overextended with my arm reach. I'm sure I could make the 58 work, but all in all the 56 just seemed a better fit. I'm going to pass on the used CAAD9. New development: Today at the LBS I test rode both the CAAD10 and the Synapse, which has created another conundrum. The Synapse, with it's more relaxed geometry, was to some degree more comfortable than the CAAD10 and probably more conducive to my non-racing riding needs. However, my LBS is located in a little village with lots of winding streets and turns and when I test rode the CAAD it was way to cool as to how nimble and responsive that bike was. Gotta think this one through.