The mod will let the strap "stretch". So when you feet need more space (swelling), the strap won't interfere your feet expand. Anyway this my two cents worth.
It's possible I don't understand the mod. The shoes are snug when I put them on, but not uncomfortably so...though the tip of my big toe touches the end of the toe pocket. Since my old pair are 43s and probably ARE a bit too big, I'm wondering if the small amount of soreness that resulted from my 1-hour workout was part of the normal break-in process that comes with a new pair that fits well.
I just don't want to get 10 miles down the trail and realize they were the worse choice, you know? Especially if y'all could say pretty definitively that I should go with the larger ones (despite the fact that there's a gap at the heel when I walk).
The 43s are too big for you - now sell them to me !! 
You might as well buy them directly from REI...they still have 43s in stock for both the black and the brown: http://www.rei.com/product/843161/vibram-fivefingers-kso-trek-multisport-shoes-mens-2012-overstock
It's something like $33 after tax with free shipping on orders over $50 or free to your closest REI (if you have them near you).
