I like the new lens! Although I must be honest, even if I did have the moeny, I wouldn't trade my "old" 100mm macro for it. I don't think I will be a lot more satisfied with this new lens. The Is is really a good feature, but since I use flash like 9/10 times, I don't really see the real benefits for macro. For other purposes then macro, the IS is certainly a good feature to have. My opinion: a great lens, but not really a major step forward on the earlier version.