I fully agree about variability in shoe shape and fit AND about variability with different production runs of the same shoe. I get curious about sizing when I'm contemplating mail-order (fits of winter boredom!!)shoes. In a more rational state of mind, I'm fully supportive of the fit/size drill...
1. Shop late in the day (when feet are bigger).
2. Wear your "normal" hiking socks/sock combination.
3. Take your time in the store...walk around, use any ramps or inclines they may have.
4. Try on different makes/models/styles to find the sweet spot of fit.
5. After selecting your favorite, take them home and wear for an extended period indoors to verify the in-store impressions. If there's any doubt, take 'em back an try on something different (even the same model, same size but a different pair could be a different fit).
I appreciate input from those who are willing to share experiences, good or bad. Thanks!!