I haven't used the HD449's, but I use to own both the Denon D1100 and Creative Aurvana Lives. Even if they were the same price, I would easily choose the Creative Aurvana Lives over the D1100s. Not that the D1100s were bad, but the bass is a bit TOO emphasized for me to the point where it drowned out everything and gave me headaches. The build quality on both aren't the sturdiest, but the D1100 had lots of creaking which other members here can also attest to.
The Creative Aurvana live's have been some of my favorite pair of headphones (If you look at my profile, you can see the other headphones that I've owned before). I think for 70 dollars range, it'd be very hard to beat the CALs.