Which of these is a better macro lens for Nikon D90 and why?

I'm torn between getting the Tamron 90mm f/2.8 AF Di or the Nikon Nikkor AFS 85 mm/3.5 VR as a macro lens. I've read good things about both, but still not sure. Weight is a big factor for me, as I travel a lot and I don't want to lug anything heavy around. both of these are light. The VR is not a big deal for me, as you don't really use it anyway when doing macro work on a tripod. Thanks for your input!