Rockhopper wrote an answer about Scarpa Vapor V Climbing Shoe - Discontinued Vibram XS Grip2 on April 7, 2013
So I sized down 1.5-2 full sizes from my street shoe when I bought these. The first time climbing in them was borderline torturous honesty. The left was so tight that any flex at all seemed like my foot was in a vise. That first day I continued to wear them for short periods of time and walk around a bit and take them off, repeat ect. and did couple days of short routes that were not too demanding. After the third day out they broke in dramatically, and after about 10 days out, they fit perfectly and I love them! Hang in there, they will be your favorite shoes in no time!