Rick Chen , Jul 17, 2012; 01:27 a.m.
My 2 cents: the 105mm VR is very sharp, but it might be too sharp for portraits. Because it's a macro, it's focusing speed is slower. The 105mm range is good range for portraits.
Many felt the 85mm is too wide, but it has a great subject separation at f/1.8. That also depends if you are on DX or FX, for DX the 85mm is ok I think.
If you think $300 is not much, you can use that to get a used 90mm tamron f/2.8 for marcro (works with low end DSLRs too in AF) and you get the best of both worlds.