My carbon road bicycle is 172.5 . My touring bicycle is 170. The around town 7 speed 170 also. And I did have a track bicycle with 165 cranks.
Each bicycle handles so much differently that I don't think that I can tell any great difference in crank length. Maybe with the track bicycle, but fixed gear is so much different. I also had a road bicycle to fixed conversion, no markings on the crank. was the difference fixed gear or crank length? I wish I had the extra $$ to try out 180 cranks on the touring bicycle. But alas. I'm 5'8" with 52 cm bicycles.
So what's your opinion and/or experience?