Ok, I'll attempt to address some of these questions. LOL about the confused comment
A "full frame" sensor is basically just a term used that means it's full size relative to the older "35mm" film cameras. The full frame sensors are 36mm x 24mm in size. The D300 sensor is 24mm x 16mm, that's where the 1.5x crop factor comes in. So the 5D sensor is 2.25x larger than the D300 sensor (1.5 x 1.5), and much more expensive to produce, along with a bigger mirror and mirror box, and a different prism system needed. So with a 12mp 1.5x crop versus a 12mp "full frame", the photosites of the full frame sensor will be MUCH larger, and all things being equal will be of higher quality, and less noisy. They'll also have greater dynamic range. That's the reason the 12mp point & shoot cameras look like absolute [bleep] compared to any 12mp slr. The P&S sensor is about the size of your pinky fingernail, so the photosites are tiny. So pixel size is a major factor, that's why when stepping up to higher mp sensors, going full frame will yield a better looking image (again, all other things being equal).
The new Nikon D3 is a 12mp full frame (their first)... that's a better comparison to the 5D, but it's $5000.00.
Sure you could make a valid comparison, D300 to 5D, and yes it is still a current camera. My point was just that that's old technology for Canon (3yrs in dSLR's is a lifetime), if you compared the 5D to Nikon's slr's from 3 years ago it would be a joke, literally. Plus, Canon is due to upgrade that model before the end of the year.
I think I touched on most of it, but if you need any further clarification please let me know.
Rob
