I gotta say, I really liked the demo.  I will agree, the cars seemed a little 'light' feeling, and I imagine it would play a lot better with the wheel (which I haven't bought yet).  I will definitely be buying this one (soon as I find a decent price). 

Between this and Forza 2, I think I'm going to be spending a *lot* of time driving this summer. :D  That's not a bad thing.

Just try to remember that  the demo is actually behind the retail game in development by weeks or months.  Also realize that they may use different textures/models and other stuff in the demo to save space and time.  There may be many things that get changed/fixed between when the demo is made and the game goes gold. 

Frankly, I think Codemasters did a better job with the Dirt demo compared to the Forza demo.  I think the Forza people could have given us a bit more variety.