actually, the sizing is largely dependent on your comfort level with shoes. I have a the 995(just nice) and 988(a little roomy) in size 42, and both fit comfortably for my size 40-41 feet. I also have a pair of guidi lace up boots in size 41 which are snug but not to the point of discomfort.(can't remember the model number)
my foot is about 26-26.5 btw.