I was interested in the macro lens because it's optimzed for close-focusing, and I do a lot of close-focusing, though with the macro I probably wouldn't be using close-up tubes, which was part of the advantage; but maybe you're right, would I be better off buying the 180 or 150 (or the 160 CB) and just using close-up tubes with them? Would I really see any difference between them and the macro?