Personally, I'd take a EC-D over a Demo 8. No, I've never ridden either of them but being a graphic designer, I just like the look of the EC-D better. The Demo 8's used to be one of the toughest looking bikes out there, the last 2 years they have become this "curly Q" pregnant looking thing. Yep, that's just my opinion and I'm talking DH bikes here.
Then look at the prices: EC-D $2,999.99 complete, $1,499.99 frame only.
Demo 8 $,4900.00 complete, $2,200.00 frame only.