I am an advanced intermediate skiier, and I have finally decided to get new, good boots. I was measured by 2 separate boot fitters and they both thought I should be in 26.5s. They both checked between the back of the heel and the shell and said the fit was good. The problem was that I probably tried on 6 different boots in that size, and they all began to cause foot pain within 10 minutes in the store (fairly diffuse pain, but seeming to emanate from the instep area-- I have a high instep). I finally tried on one pair which didn't cause pain after about 20 minutes (Fischer Soma X100), and I bought them.
But I have now tried them twice on the slopes and I actually had to take them off after 20 minutes of skiing both times, due to severe pain. Front-to-back they feel fine (toes just brush the front of the boot when standing, and are not quite touching when I am flexed forward). The pain seems to center around the proximal half of my foot, i.e instep. Ankle and toes are fine, except that my toes get tingly. The width seems OK too. But the foot pain is not just mild. I really can't continue skiing after 20-30 minutes.
My buckling technique is to buckle the 2nd from the top buckle, then flex forward/bend my knee a few times, then buckle the other buckles (other top buckle, then the foot buckles) and then the strap. I am definitely getting the heel in the back of the boot as I buckle. I have Superfeet insoles.
My question is really whether I need to go up to 27 or 27.5, or whether I should do something else to try and stay in these 26.5s.