I love it. It's so nice not to have to change lenses all the time and the image quality is quite good. I had been using my dad's 17-35mm 2.8 which is an incredible lens, so I was skeptical on the image quality of the 18-200. As you can see, it's quite sharp. That's basically a 1:1 crop shot at 200mm. If all my photography was in a fairly narrow range, I'd think about spending the cash on a 17-35mm or whatever lens in that class would give the range I needed. This is quite respectable though and I don't need a bag of lenses all the time or the risk of dust on the sensor.
The D300 is fantastic. I've had it since they first came out, I think it was from Berger Bros' second shipment of them. Now it has well over 18,000 exposures on it without missing a beat. Built like a tank, magnesium body and pretty reasonably weatherproofed. Certainly not waterproof, but I've shot in light rain and snow with no issues at all. It's only real downfall is the cropped sensor, which the D700 takes care of, but for a significant price increase.