Hello, I have got a Macbook Pro 13" (2012) and I have seen many threads on performance with 10.11 with retina, but hardly on non-retina. So I decided to install OS X 10.11 on my mac as many people said it is fast enough. So far, (12hr usage), the battery life is as good as Yosemite, the performance... 10/10. Every app loads in at least one second, surprising as this is an 3 year old mac. Btw: With my SSD (external) it is blazing fast. This is something that I have anticipated in OS X for many years.