I have the budget to buy one of these two great lenses. I know they serve very different purposes. My question is... which one will give me better bokeh and color rendition when used for portraits? I am a hobbyist who shoots portraits occasionally-- usually under controlled conditions (with off-camera flash and a reflector). I can almost always move to a good position, so fixed lenses are not a problem. I do a fair amount or nature shooting. I'd love to have the 70-200 f/4 for that. And I enjoy doing macro shooting just as much. I'd love to have the 100 f/2.8 for that. But I can only afford one or the other this year. So portrait performance alone will be the tiebreaker. Any recommendations would be appreciated, especially from folks who've spent time shooting portraits with both.