Pros: It does work, but not to specification.

Cons: In my Asus motherboard with an AMD CPU, this RAM will not even allow boot as far as BIOS in automatic configuration mode, but just hangs at a black screen without even a beep. If before installing this RAM I set the BIOS to limit the memory speed to 400MHz (that is, DDR3-800), the computer will boot correctly. Even increasing the memory speed to 533MHz (DDR3-1066) fails. By contrast, the old RAM (2x2GB) worked flawlessly at the automatically detected 667MHz (DDR3-1333). Polling the SPD directly with the CPU-Z utility shows that this RAM reports XMP-1600, but the highest JEDEC standard speed supported (that is, without Intel XMP) is DDR3-1333. Where motherboards do not implement XMP support, especially if they have AMD CPUs (as mine does), the highest automatically set speed will be taken from JEDEC standard. I suppose it would be possible to set the motherboard manually to access this RAM at DDR3-1600 speed, assuming that it would work if supported for XMP, but this is technically overclocking. Because of this, in my opinion this RAM should not be listed as DDR3-1600 without at least some further explanation of this issue. That said, if I could get this to work at DDR3-1333 JEDEC standard, this would be a 4-star review. In fact, since I can't get it to work faster than DDR3-800, which is the minimum speed of the motherboard, it is instead a 1-star review. More importantly, I have reservations trusting this RAM at all, given its flakiness.

Overall Review: Buy something else. RAM should not require this much effort to get working.