I am thinking of getting a set of 160's. down from 175. From what I hear the shorter length with the lower gear like my 42x15 helps with spinning out, or at least helps with high cadence and of course pedal strike... Eddy Merckx frame in a dump, you lucky dog!

Oh yea and I don't think you will notice a difference in crank length between bikes since it is an integral part of the drive train. Changing length on the same bike may be noticeable since you have the same gear ratio.