Simply put, how good are they? Specifically, these models.
http://www.ncix.com/products/index.php?sku=10167&vpn=GSA-4040B-OEM
http://www.ncix.com/products/index.php?sku=10548&vpn=LDW401S
http://www.ncix.com/products/index.php?sku=10167&vpn=GSA-4040B-OEM
http://www.ncix.com/products/index.php?sku=10548&vpn=LDW401S