I am using a fairly old MacBook Pro 13" that is a hand-me-down. It was running Mountain Lion when I got it. I upgraded it to Yosemite and recently to El Capitan. Both seem to run very slow. I am debating whether to downgrade to Mavericks. I have looked at the various tutorials online on how to do it and feel fairly confident. But, I would like a second opinion on if it is worth the time and energy. Here are the specs of my MBP: Model Name: MacBook Pro Model Identifier: MacBookPro5,5 Processor Name: Intel Core 2 Duo Processor Speed: 2.26 GHz Number of Processors: 1 Total Number of Cores: 2 L2 Cache: 3 MB Memory: 2 GB Bus Speed: 1.07 GHz Boot ROM Version: MBP55.00AC.B03 SMC Version (system): 1.47f2 PS: I looked at the requirements. 2 GB for El Capitan. I've been reading that Mountain Lion is a much better OS than Mavericks and it is listed in my purchased apps so I might just downgrade even further.