In progress: Canon EF 100mm f/2.8L Macro IS
Related: Canon, Canon EF, Canon EF 100mm f/2.8L IS Macro, Canon Lenses, color space and gamut
With the first sample showing clear problems, one of the first things I did with the replacement EF 100/2.8L was to check infinity sharpness across the field. Based on perfunctory checks, this 2nd sample looks to be vastly better, so I can now proceed with the review. The partial review to date is in DAP, and it includes details on the behavior of the bad sample, including a comparison with the Leica 100mm f/2.8 APO-Elmarit-R.
B&H Photo now has the 100/2.8L Macro IS in stock 
as I write this.
Canon 1Ds Mark III + EF 100mm f/2.8L Macro IS
The rose example below is well out of gamut in sRGB, looking flat and dull, nuances lost, a nuance lost on those who think sRGB jpegs are fine. It’s even slightly out of gamut in Adobe RGB, which is why I present it in ProPhotoRGB colorspace: you should be using a wide gamut monitor with 12-bit internal calibration, like the NEC LCD 3090WQXi. Otherwise, you just cannot see what’s there, a severe problem with reds, a fact that hits one over the head when what couldn’t be seen is revealed! Especially with today’s wide-gamut DSLRs, like the Nikon D3x, you’re looking at a crude approximation on some monitors.
If this rose image looks either garish or grayish dull, it’s because you’re not using a browser that is not colorspace-aware. Firefox 3.5.3 displays this image badly, even though it’s supposed to be colorspace-aware. I recommend Apple Safari 4 (for Windows and Mac).
Canon 1Ds Mark III + EF 100mm f/2.8L Macro IS @ f/2.8, 1/8 sec handheld
This backyard scene below won’t grace any calendars, but I made a sharp image handheld with image stabilization at 1/8 second (3 shots, two were blurred). Like the previous image, tones just turn into undifferentiated dull red mush in sRGB, so this image is also presented in ProPhotoRGB. Be sure to use 16-bit mode when working in ProPhotoRGB.
Canon 1Ds Mark III + EF 100mm f/2.8L Macro IS @ f/2.8, 1/8 sec handheld
JPEG whacks the reds somewhat also (or maybe it’s an 8-bit thing), even though this is saved at quality=80.
