I read the review of the Sidi boots. What I would like to know is what size I would need. The Alpinestars Tech 6's I have don't come in 1/2 sizes. I ended up getting a 9 which was very snug. The 10 had too much play. Are Sidi's the same size as Astars. They do come in 1/2 sizes. I wear a 10 in everyday shoes. Thanks for any help.