I installed Sierra clean from usb, and so far it has a few niggles, worst one being wake from sleep being annoying and so slow to wake, sometimes have to hold power button and reboot. another is my network HP laser printer, see's it and installs it, but no way I can print to it, says printer idle, have to connect via usb now to print. I don't think there is any great advantage over El captain, infact think El was faster all round. and I have to say since using win 10 I might even ditch Mac and go back to PC as win 10 is a good OS and I won't be stuck with slow hardware like on Mac. there is no need to keep bringing out new OSX every year, just get the current one working 100% I still think pad's and phones is all Apple is interested in now, in the desktop market Mac is way behind in hardware.