Mid-2012 MBP with 2.5 Ghz i5, 4GB ram here. I thought Mavericks sped it up, but Yosemite is unnoticeable. I couldn&#x27;t tell you if it is faster or slower than when I bought it, to be honest. All the problems people mention in the thread, I&#x27;m somewhat surprised by. I guess I&#x27;m lucky enough to not have wifi issues, rely on iTunes, or Apple Music.