In sizing up, the shoes still have to fit me in that they do not slip in the back and cannot be too wide in the forefoot, while still offering room in the toe box. Same with my running shoes. There's no way that I could wear the same size that I do in street shoes--at least not without killing some toe nails. I have to wonder whether you just haven't found the right shoe for your foot. Go to Rusted Moon in Broad Ripple (or REI when they open up) and try on a bunch. I cannot buy hiking or running shoes without trying them out first, even with brands that normally work for me.