nice to hear
I dont know what's considered a good opening, I just know that if you can close it fully, its too large and you cant fix your foot obviously. 1/2 cm sounds pretty acceptable to me.
Also, for me there is quite a big difference in how swollen my feet are between a warm summer day and a cool autumn/spring day. Something to think of when you are trying out shoes in cold weather.
Great thanks for your help I think I will go ahead and but a pair of Alex in that case!