Who has installed El Capitan on their 21" iMac from mid 2011? That's what I have and I'm curious to try it, but figured I would see if anyone on here has similar specs as me and could chime in? My system: 2.7GHZ Core i5, 1TB 7200RPM drive, 16GB Ram, AMD Radeon HD 6770M 512MB Video. I have manual backups, Time Machine Backup, iCloud Backup, CrashPlan Cloud Backup. Yosemite works fine, but has really slow startup time. It was zippy on startup in Mavericks. I figure that's more to do with an old moving parts drive since SSD would be better. If they don't release a better iMac this year with retina display, I may mail it in to OWC and have them install an SSD under their turnkey program.