It's an old CPU, but if you're upgrading an older machine with a dual-core, it's a decent upgrade. Clock speed not as fast as other quad-cores, but this one is much cheaper. It dropped right in to my old Acer and worked great.
Three of the four sticks worked without issue, one immediately failed memtest. Tested that stick on another motherboard to make sure it wasn't a board issue. Otherwise I'm happy with them.