Anyone play badminton?

I've been playing since the start of this year I think, and the racquet I'm using is the Yonex Armotec 700. I switched over to badminton from tennis mainly because I couldn't find my coach anymore It's a pretty fun sport, one that's easy to pick up, but a little harder to master.
I was flicking through my froogle search and found this:
http://www.opentip.com/product_info.php?cPath=1_4_111_373&products_id=46679

E-4431 Training High Quality Feather Shuttlecocks

Anyone play badminton can help me to make a judge of those Shuttlecocks?
If they can last longer in training or advance I think it is pretty good deal(bascially $0.8 per shuttlecock) compared to other brand at it's price.

but as I've never played with them before I have no idea of their performance, does anyone have any experience with these shuttles at all? Any help would be appreciated, thanks!