I have been thinking of getting either of these two lenses. I already have the ef 70-200mm f/2.8L IS USM and the ef 24-105mm f/4L IS USM that i use on a Canon EOS 5D Mark II full frame sensor. I am thinking the Macro lense would be best for me. then i would have all ranges covered for what i would like to do. What do you think and what are your opinions on these two lenses. reviews that i have read both are very good. I just feel since i already own a 70-200mm f/2.8 that i wouldn't be gaining anything from the 85, but maybe i am missing something. I do want to do Macro but how good is the macro on the 100? This is not the L series lense with IS. I don't think i need the IS with macro but i never shot macro before so i don't know. Please let me know your thoughts.