EightD does have a really nice feel to it. It's got a soft, smooth feel and it isn't nearly as shiny/plastic feeling as some other fabrics. However, it's also a lot less downproof and more air permeable than some of these other fabrics in my experience.
I had an M55 quilt (which I believe is basically the same as the 'new' M50 as the new M50 is being toted as more downproof that the original M50) that I never ever saw the tiniest bit of down come out of. It was a bit slower to loft (because of the low air permeability) and a bit plastic feeling, but I really liked how downproof it was and how it totally blocked the wind and water beaded off thanks to the Teflon DWR.
My current quilt is all EightD. While I like the feel of it better than M50/M55, a moderate amount of down does come out. Not a problematic amount, but more than I'd like. There's always a tiny feather or two trying to get out despite it being 900fp down. Going forward it's definately not my first choice for the shell - no need for the ultimate feel there, I'd rather have more downproof, wind proof and water repellant. The teflon DWR's on the M50 stuff should be the ultimate for the outer shell. Even for the inner I'd rather a fabric that is a bit more of a compromise towards downproof, but EightD is acceptable.