What many perceive as memory "Quality" is actually nothing of the sort.
In today's competitive Mac memory marketplace, the main issue with RAM is compatibility with your specific Mac.
Established Vendors who provide a money-back guarantee if it does not work in your Mac, in conjunction with a LifeTime warranty, are selling only high-quality RAM built with chips from major manufacturers. Anything less costs them money.
Some Vendors maintain the integrity of their product by developing substantial expertise, including owning Macs and plugging modules into them. This Vendor is such a company:
http://www.datamemorysystems.com/G5_Memory.asp
Some vendors, Crucial in particular, maintain a large database showing which sales "stick" and which are returned. These returns are eventually reflected in their advice, but there are numerous examples of screw-ups in their database resulting in wrong modules being delivered, or incomplete options offered.
As a technical person, I am deeply annoyed by Crucial's business practices, especially their touting the "Quality" of their memories at the same time, and I will not do business with them.
Message was edited by: Grant Bennet-Alder