Hello everyone, so I've ordered a Samsung 850 EVO 250Gb and 8Gb RAM from Corsair to revive a family members' MacBook Pro 13" late 2011. It's a known fact in my field of work that Apple computers get slower with (major)updates. Therefore some of the workstations we use still run on Mountain Lion and even Snow Leopard for stability and performance reasons. Some color correcting stations run hardware upgraded MacPros (the aluminum ones that came before the latest 'trashcan' design) with El Capitan. I've done a lot of reading on different forums before deciding to go here to ask my question since the member base here at Mac Rumors seems more educated and therefore more 'critical' against the Apple products instead of the standard 'whatever-Apple-says-I-do-and-they're-always-right' -attitude that is found almost everywhere if you google your problem. Myself for example, I have an MBPr mid 2012 that I downgraded back to Mountain Lion because of Mavericks bad impacts on the computer ; the battery drained extremely quick, the computer heated up ridiculosly much running easy programs, crashes became more common and it became generally much slower. I'm curious if the latter OS X versions actually hve some performance advantages on the MBP that's currently running Lion.. So, which macOS/OS X should I install for the MacBook Pro 13" late 2011 ? I've the possibility to install: • Lion • Mountain Lion • Yosemite • El Capitan • macOS sierra I'm more thinking towards El Capitan than macOS sierra, is that a good idea? Please share your experiences!