So I've tested the fov thing a tiny bit, but not sure what the information I found means. What I did was go into a bot game, put cheats on and try to change the fov_cs_debug to 90, then 100, then 106. It didn't change with the first, and the got wider with the other two, on a 1920:1080 resolution, 16:9 (my monitor's native). So clearly the default value for fov_cs_debug is 90.
As I said, not sure if that means 90 is default horizontal fov for 16:9. Just throwing some info out there
Going by feeling, I never noticed much discrepancy between tf2/l4d2 (steam games, not affected by fov) and cs:go on 90. I thought I felt it was a bit different, but I thought it was due to the fact how cs plays compared to the other two, and how accuracy is much more important. Either way, not 9 cm different, but who knows.
edit: Oh, nvm, wizard already answered. I'll leave it here anyway.