I put this memory in my 2013 iMac and now it runs faster. More files are stored in RAM cache and less time is spent compressing memory. Well, I'm not sure about that 2nd comment but it sounds good.
If you decided to do this upgrade, be careful with the antenna wires on the motherboard. One of the connectors broke for me and there is no easy way to fix it. So far, this has not been a problem.