Hi guys I have an early 2011 MBP. Right now it's a Plex Media Server, organiser of photos using Lyn, an iTunes library and phone syncer, and a web browser. I think that's pretty much it. I don't use iMessage, mail, or any iCloudy things. I got it with Snow Leapord and it's had every update to 10.10.5. It's getting slow, so I'm considering a clean install. 1. Do you think a clean install will help. I read that a clean install should never be required, but find this unlikely. It's had Lion on it! That was a disaster! I only know one person that has done a clean install on an old iMac, and he said it gave his computer a new lease of life. 2. If you think a clean install will help, which version of OSX do I choose for my aging machine. I need at least 10.7 for Lyn, and 10.8 for shootShifter but I could possibly live without this. But if I recall Lion was a battery wrecker, so I'm not inclined to go for that. I'd obviously like the latest and greatest, is this ok on an HDD? 3. Later this year I'll be getting a big fat 1TB SSD (because I hear this will b amazing) and upgrading to 16GB of RAM (because it's reasonably cheap, so why not). Is the general opinion that this is a good idea? And does this change your opinion on the OSX version? Thanks to all!