I use this lens for its duel purpose. For weddings, it's phenomenal at capturing the rings, cake details, dress details, etc. It is not my go-to must have by any means, however, I can count on adding an additional 40+ images to someone's wedding when I include this lens in the lineup.
I really have done little work using it as a portrait lens. For portraits, I use the 85Lii for slow/non moving people and the 70-200ii for faster moving work.
As a macro/detail lens, it's a keeper for me.
I hope this helps,