Initially ordered this product through Amazon from Kikatek, it being the cheapest for me at the time. Speedy delivery, with adequate packaging.
Installing the sticks was a bit of trouble as the heat spreaders get in the way of where you want to push down, and I didn't really want to apply too much pressure to the sides. They eventually went in, but I had to push the very corners to avoid any kind of damage.
Computer running Windows 7, Asus P6X58D-E mobo, i7 950 CPU started up fine with the new RAM. As you should always do, I then ran Memtest86 to test the RAM for errors. After an hour, however, there was a huge list of errors that was constantly being added to (I had gone away while it was running the test). I rebooted and ran the test again. Sure enough it errored again. Even though the computer appeared to be working fine, those errors could hit me in something I am doing 3 years from now, which is bad.
I decided to remove the sticks and test them one at a time in the same slot to determine the cause of the error. The first two sticks I tested ran fine for about 4 passes, but the third stick did not even make it through 1 pass and had the multiple errors.
So I contacted Kikatek about the problem and got a quick reply without fuss asking me to return the product. Sadly it wasn't a free delivery, but I was kept up to date on the progress of them receiving the item, and dispatching the replacement. As I had also moved address in the time that this occurred, I asked them to send it to my new address and they did so swiftly.
Upon receiving the replacement, I tested it and it ran fine through about 4 passes, so I concluded it to be error-free. I have now been using it for a few weeks and it works fine.
To conclude, I rate the product at 4* because although, it works now, it was faulty so the consistency could be better. I rate the seller, Kikatek, at 5* though because of their good service.