Sorry back track, I used Tamaron 90 too, I dun see much a different actually. Do you mind sharing the different?
I agree that AF is slower and it hunt more frequent but dont we use manual for Marco. For portrait we will both use our 70-200 for the job.The Focus cannot be override but it is okay since we use manual.
The only disadvantage as a Marco lens is that it extend so just gonna be careful about the front element and it feel too plastic compared to 105 tank
But for about $600 lesser in the B&S, he only give up VR, focus speed, and a bit of build quality from the Nikon 105mm. For $600 he buy a 85 f1.8 and $480 or a Tokina 12-24 and still have much to spare. But for people with budget and nikon die hard we follow nikon all the way unless they really do some crap products out.