Shoes are extremely personal as you can see by OM and Gershon's replies above. Get shoes that fit your feet today... not ones that fit your feet yesterday. Foot shape changes with time, so go see if you can find a better fitting shoe.

Blisters are caused by many factors but mostly by shoes trying to change the shape of your feet. Moisture and heat do seem to make blisters worse, which is why I would be leary of advice to use GTX boots. Perhaps in Afghanistan, where it is very dry, keeping every ounce of moisture possible in your foot is for the best.