Kevin I love the Sigma, bought it after looking over the 80-400 VR nikon and I can honestly say I have no regrets, takes great photos and for F4 its quicker then I am a real good when in manual, best $900 bucks I ever spent.... I would love the 300 nikon but could not justify the money at my skill set
Meant to thank you before for turning me on to the web page that you have your photos on, real nice stuff and enjoy looking thru the work of others.
Given that you next to nothing for a trade maybe I will save for the D200 and use the 100 as a back up. (wife will kill me