Hi. I moved from a D80 to a D300 this week. I have never owned or used a D200 so I can't compare the D300 to it directly, but I can compare it to the D80 for what it is worth. Here are a few quick observations: Feel: As you would expect from a Nikon, it feels great in the hands. Button placement is good. ISO: High ISO performance is MUCH better than on the D80. Ken Rockwell has stated that it is not better than his D40 at high ISO... he is smoking dope or something, there is absolutely no comparison between the two. I think it is because he was testing it by taking night shots or something... that is not how I compare high ISO... to me, what matters is the ability to take real pictures of real subjects in low lighting conditions where you cannot use a tripod, or where the subjects are moving. Taking pictures of lights in the neighborhood at night and comparing them is not nearly as useful to me as taking shots of a basketball game in a badly lighted high school gym. Heck, if I want to take pictures at night around the neighborhood, I will put the camera on a pod and turn the ISO DOWN, not up. Anyway, the body focus motor is strong. Battery life is good, and will be better when I stop playing around with the menus and chimping every shot. I haven't shot with a D200 but I have looked at them a lot... the weather seals on the D300 seem to be more robust. The sensor cleaner thingy is just a button in a menu. I pushed it, but the sensor was already clean so I have no idea what it did. There were no bells, whistles or vibrations. I guess we will see. It comes with Capture NX for free, which is a HUGE plus for folks who don't own the program already. Capture NX, to me, is an absolutely irreplaceable part of my work... it replaces 95 percent of the masking work in Photoshop, and saves a TON of time to get as good (if not superior) results. It does not, however, replace Photoshop, I use both. I haven't figured out the LiveView yet, but then again I haven't really tried either. I haven't got a chance to use the camera much, but I will post more observations when I can. I plan to be going to the St. Louis Zoo Zoo this weekend just to shoot a familiar subject and learn what I am doing. If anybody has specific questions, I will try to answer them as best I can.