Thanks bricky21, for your response to my question "I need some help understanding the Q factor and how it applies to my knees."
This gives me something to evaluate with my knee position relative to my foot.
For a little additional detail, I was fitted to my previous bike, but over the winter picked up a S-Works Tarmac which I have been feverously swapping parts out on to get it ready for this season. This is the bike that I am putting the Keywins on. I have a professional fitting scheduled for March 16th on this bike. When I assembled the bike I set it with similair measurements from my previous bike and I have already given myself an informal fitting and tweaked the setup a little from time on the trainer. I am generally happy with the current setup but have only logged two long outdoor rides to date. The previous mentioned knee discomfort was on my previous bike and was corrected as stated above. My new bike setup is as close as I could get it to my old and I did not experience any knee discomfort on the new bike setup.
Since I have never riden Keywin's and am attempting to ride more with my kness tight in (for aero reasons) the option of the shorter axle was a consideration and wanted to have them on the bike for the scheduled fitting. After that, it would be easy to get the standard or +3 if reccomended by my fitter.