I know when I was looking to buy this lens I seen many people claim that the 135mm f2L is sharper than this lens, they may be right but if it is then I can't imagine what it's images look like. This lens is insanely sharp and shows so much detail, especially in portraits. I'm very thankful I picked this lens and not the 135mm even though I'm sure it's a great lens.
all macro lenses are sharp to show more details for small things
other primes lenses are sharp but not like macro lenses
the 100L with IS and the 135L without IS , it's need a shutter from and over 160 to get a photo in a great focus