This is my second maro lens (first was Canon 60/2.8 macro, I used it with Canon 60D for 3 years).
What can I say about this lens? It's sharp like 60/2.8 (I don't see big difference in picture resolution, maybe at f/2.8, 100/2.8 IS is sharper, but I think it's a matter of sensor in 80%), it has IS and it's weather sealed. Video quality is much more better (on 60D videos are more blurred and there's a medium level of moire).
Lens is very good, but I don't like noisy IS (I have a Tamron 24-70/2.8 VC and there's no sound of VC in my videos). AF works fine, but it's very slow in the low light conditions.
There's a lot of reviews of this lens and my english is not good enough, so watch my photos and videos ;)
Video (max quality, ALL - I, 30 fps):
Aperture - f/6.3; shutter speed - 1/100; iso 500 (1:1)
Aperture - f/13.0; shutter speed - 1/80; iso 2500 (no iso reduction)
ISO tests (6 shots).
Because quality of these pictures are not the same as on my pc (due to high compression), you can download two RAW files (with iso 10000 & 12800):
Here you can compare iso between 4 cameras on the image comparison tool (there's 7D mark II):
Aperture - f/5.0; shutter speed - 1/250; iso 100 (I used Sigma 610 dg st flash)
Aperture - f/2.8; shutter speed - 1/160; iso 500 (cropped)