With a smooth AI lens, you will want to manual focus.
Call me stupid, but I feel more like I am "making" the picture if I manually focus it.
If you make a nice portrait or two using a manual, you'll have this satisfied feeling of "I 'make' this picture". I don't know, it's hard to explain. My partner (who isn't even into photography) feels the same too.
My Tamron 90mm macro is now, well, becoming a portrait lens, lol. The result is just that good. If you have time to go to camera shop, bring your D2X and have a go at it. Shoot the sales rep behind some lighting in the background (around 2 metres behind and don't use flash), and shoot it wide open, and you'll see what I'm talking about.
But the outdoor performance is the great thing about this Tamron (background and bokeh to my eyes is superior to Nikon 85mm 1.8). I've tried my brother's Nikkor 105mm 2.8 macro, didn't really like it for portrait either.
Anyway, the seller hasn't got back to me, now I'm getting worried that he might change his mind. Well I hope he isn't because winning the bid = contract. But you know eBay...