I rode and raced on 172.5 for 10 years or so (6' and 32 inseam), then started riding mountain bikes with 175 cranks. Then I switched to 175 cranks on the road....and played around with lowering the saddle but found I liked the 175 cranks best with NO CHANGE in seat height. Over the past 5 years I've switched to more spin, less mash, and raised my saddle by about 10 mm. All in all it is not much change and a very personal issue