Out of the best photos you have taken, how many best shots you have done with Canon IS/Nikon VR turned on? How usable is it in practice e.g. can you handhold at 1/5 or 1/10 second when shooting at 28mm ? Is IS/VR battery-hungry?
It seems like Canon is very slow in introducing IS to its lens, make me wonder if IS/VR is actually that useful. Why don't Canon come out with 70-200 f4L IS where it will be more useful say compared to 28-135 IS ?