There is a really cool new invention for rifle hunters. It helps protect your gun and your shot. It will NOT affect floated barrels. You can see the video on how it works at RRRgunrest.com
This seams like a neat idea. I only hope that it doesn't change the balance of the rifle much. For any that are light in the front it might be perfect.
I've used those too and it still doesn't supply the sturdy rest that the RRR does. Slings slip, this won't. No repositioning of sling either. Just makes your shot a lot easier and more accurate.