Excerpt: This lens, while a little heavy (the 75mm and the 150mm seem so light weight in comparison), is exceedingly sharp. Once you see the detail using it on the 645D body, the weight issue disappears.
Excerpt: I'll join the chorus singing of the sharpness of this lens. I have both the A and FA versions of this lens; I will sell one of them at some point, but it's hard to do. The 120mm macros in either version are the sharpest close focus lenses I own.