i just upgraded from the Sigma 24-70 DG to the Canon v2.. and sharpness just reached a whole new level!
at the same time, i value VC a lot, for two reasons :
1. i drag the shutter for some motion shots (usually at 1/5s)
2. to compensate for 5d2's inability to manually fine-tune their Auto ISO function.
for users who have experienced both lenses, how do you feel about the drop in sharpness/color/contrast from the Canon v2 to the Tamron? I already know how good the Canon v2 is, but i'm not sure whether the Tamron can also live up to my expectations. seeing sample pics is a mixed bag, cos there are so many lighting conditions and skill levels from photographers.. so it's best to hear from the horses' mouth.
TIA! 

