I guess your question about VR vs. f/2.8 has to factor in as well the brand of lenses.
Nikon vs. Sigma is like comparing Apples and Eggs (no pun intended
I would choose Nikon over the "budget" brands anytime. Perhaps the only exception is the Tokina 12-24.
Reading your post, I would choose the Nikon 18-200VR if I were you. Would choose it for its convenience and VR (no hassle of changing lenses and hand shake).
Hope this helps you
Nikon vs. Sigma is like comparing Apples and Eggs (no pun intended

I would choose Nikon over the "budget" brands anytime. Perhaps the only exception is the Tokina 12-24.
Reading your post, I would choose the Nikon 18-200VR if I were you. Would choose it for its convenience and VR (no hassle of changing lenses and hand shake).
Hope this helps you
