If you will be taking a lot of insect shots, and are impatient, then the 105 may be worth the money. If most of your macros will be of non-motile things, then I do not see the big advantage of increased working distance at a given magnification. Anyone who makes proclamations that one is always better is simply full of shit. If you are buying the lens from somewhere that has a thirty day return, use it yourself and decide if it works for you.