I'm not an expert by any means, but there might be some benefit toward trying them on at your LBS first. I had my eye on the Specialized Expert shoes because they have the "Boa dial" that lets you loosen on the fly, and they were at the price point I expected to pay. Unfortunately, my heels slid around in the heel cups and I didn't feel like spending half my riding time patching up blisters. Instead, I went with a pair of Specialized Elite shoes at nearly half the price; same size but they fit me like a glove with no slipping. I may have paid the LBS a bit more than an online outfit, but I thought it was well worth the outlay to not be riding in pain. Good luck with your search!