There are four or five versions of this lens which can be difficult to differentiate. When I first learned that this lens existed I did some research but all of the reviews had conflicting information about the different versions. Here a few of the sites I visited:
The Ken Rockwell review is the one that motivated me to seriously consider this lens.
The one I obtained has the MACRO designation but is not labeled "II" and was made in Japan. It has a seven blade aperture. This should be mechanically identical to the lenses labeled "II" but Canon's DPP software identifies the lens as the original not the "II". The software has, however, a lens profile for the original as well as the "II" so all the corrections of the Digital Lens Optimizer function can be applied.
When I look for a better copy of the lens I will probably stick to the "II" version as they will be newer and more likely to be in better physical condition. Although made in Taiwan, there shouldn't be a quality difference.
It's a small lens compared to my faster L zooms. Here it is with, the barrel extended at 105mm, along side 24-70mm f/2.8 and 70-200mm f/2.8 lenses.
My first foray with the lens was at Cohoes Falls where the shot of the walkway in my last post was made. Here are some images made with a 5D Mark III showing the extremes of the zoom range along with some HDR images of the falls.