Well I finally got some 'alone' time with an Xbox 360 demo unit, it finally showed up this afternoon at work. First off the 360 itself is hefty, it weighs more than I anticipated. It's hooked up to a Samsung 19" HD Widescreen LCD monitor and looks simply gorgeous! I really like the feel of the controller, although it seemed a little light, maybe the batteries in the wireless model will add some weight.
I finally played all the way through the Call of Duty 2 demo, and really enjoyed it. Firmly sticking to my plan that CoD2 will be my launch title. I did play around with the dashboard without the demo disc to look around at the different options. Most of the settings must have been set before Microsoft shipped the units out, as everything seemed to be set correctly. I looked around on the Hard Drive, but didn't find anything on it. It showed there was only 13GB available so the operating system must use about ~7GB like the original Xbox. It does not seem that the demo units have backwards compatibility installed because both Halo, and Halo 2 greeted me with "The disc is not from a compatible region, or the disc is dirty or damaged" error.
Here is an interesting mini-review from someone in Canada that won a system through their PEPSI promotion.