Just as parting thoughts:
Originally posted by Stiv What I’m after is a true Macro lens (needs to be 1:1) that will also take great portraits.
The Sigma 70/2.8 EX fits this description. I've used it for both.
See my first post for great macro shots by others. Here's a portrait I did:
The image is a bit soft because a) it shows a female and I did PP work to make it look that way and b) it was shot in low light and there is some shake blur. The lens itself is much sharper than this.
Yes, a longer (150mm+) macro lens can make it easier to shoot bugs that get easily scared. Yes, a shorter portrait lens doesn't require as much distance but wouldn't be good for portraits focusing on the face.
Originally posted by Stiv That's good to know, 3m is a long way when you're indoors unless your subject is standing in the corner!
Remember that this is not the consequence of using a lens that is too long, but a necessity to avoid distortion of facial features. This can also go "wrong" in the other direction: The Pentax 100mm is a great lens but personally, I find it too long for standard portraits. It will yield a "compressed" look which sometimes is what people go for, but its not your standard look.
While there are specialist lenses that are better for their respective applications (who wouldn't pick a FA 77/1.8 if they could? <- Note that this one requires even more distance), if you are looking for a "double talent" lens, I'm not aware of a better choice than the Sigma 70/2.8.