had a really good week with El Cap - no glitches, only on wakeup from the dGPU.. still want twice the RAM though (8 is not enough with virtualbox, chrome, etc)If we can upgrade then it is great, but it is Apple's strategy for us to buy a more expensive Mac. For me Sierra is stuttering on Macs with 4GB RAM or below. I think it is optimised and designed for Macs with 8GB RAM.
got a new battery in here & was getting less than 3 hours on Sierra, now it's good!I downgraded to El Capitan because of worse battery life and because I could not purge some space on the disk.
(only almost melted a hole in the trackpad when the battery started burning^^)