Dear Dipankar,
I haven't tested the Canon EF 100mm f2.8 L IS USM lens till date. I am awaiting a copy to test.

This lens is the first in Canon to have the hybrid image stabilisation system. Canon claims that this new image stabilisation system gives 4 stop benefit. I am not sure at close range ie. at 1:1 magnification how effective it is.

Considering that the depth of field at 1:1 magnification will be pretty low, one has to employ a narrow aperture like f11, f16, f22 etc to bring more areas into focus. Naturally, at such apertures, the shutter speed will be too low. Theoretically the 4 stop IS benefit sounds good, however at 1:1 magnification the benefit is supposed to be 2 stops. If you consider rule of thumb, a 100 mm lens needs 1/100 shutter speed to give sharp images. 2 stops IS benefit on that means 1/25th of second shutter speed should give sharp results. If this comes true, then in some situations you can get away handholding.

This is a L series lens. L denotes Luxury in Canon's lens lineup. So this is expected to be better quality wise.

Apart from the macro use, this lens can also be used as a general purpose lens. It would be good while shooting video. Lets see when I can test it.

Cheers,
Sabyasachi