105 is a different beast entirely compared to Claris, Sora etc.
I tend to agree (I have ridden 165mm to 175mm cranks and the difference was not particularly noticeable), you would notice a change in Q-Factor much more so (although, you shouldn't worry about this either, kind of wish I didn't say anything about it now for fear of follow up Q's, lol)[/
Dont even want to know what " the Q factor " is :-) got enough to think about . Thsnks for the info though . :-)