From what I experienced, vsync is barely usable. However, there are players who don't notice any lags and like the vsync feature.
Tearing strongly depends on the display you use. I currently have 4 different displays. My old Syncmaster 940B isn't tearing at all. At any fps count. Same for my Syncmaster 740N. My Syncmaster 943B gives me tearing in a way that doesn't annoy me at all, while my Syncmaster 206BW is just freaking horrible!
In my company we have some PVA displays, such as FSC P19, some EIZO 22" and some Syncmaster 214T. Even though PVAs are not very fast (or just for that reason???), they don't show any tearing effects.