Rock-n-Glock,
Clearly the Tapco/Leapers mount is cheaper (as in costs a lot less than the DSA). You may also be right about it not lasting - I guess time will tell. But it is a precisely machined and finished block of aluminum that fit my rife perfectly. This isn't exactly a high-tech item - it's a little tough to see what is going to fail. The only potential weak point I can see is that I've heard that the screws sometimes strip. Mine didn't have a problem, Tapco sent extras anyway, and I understand that they can be easily replaced at the local hardware store. As I said, I don't usually have much confidence in Leapers products, but in this case, I can't fault them. I've also read of quite a few posts from others who are happy with this mount. I'm sure the DSA mounts are also fine, but paying more doesn't always mean getting a better product (unless you believe advertising, name recognition, and higher profit margin make a product better).
Doug