I have the 100 f2 and my experience is that it is very fast. I only have the 24-105 and several Tamron lenses to compare it to. No experience with the 2.8. I shot this of my daughter at 8:00 in the evening with no flash on my XTi. It was at f2.5 @ 1/1000.


[img]/cfs-file.ashx/__key/CommunityServer.Components.UserFiles/00.00.00.24.67/IMG_5F00_0011b.jpg[/img]


I have posted this image a few times so some may be tiered of seeing it.


Mark