"Another major issue has the potential to ruin the day for anyone who is using the Mac for work. Office 2016 is not stable on OS X El Capitan. Brad Sams shares more details about this problem.OS X El Capitan Problems: 5 Things You Need to Know
There is a problem with some music software in OS X El Capitan, but the good news for most users is that this isn’t breaking Spotify or Apple Music, it is only impacting professional audio apps. If you use the apps mentioned here, you may want to wait to upgrade.
We are also seeing scattered reports of OS X El Capitan problems opening large photos in preview, Aperture slowing on OS X El Capitan and there are some apps that don’t work in OS X 10.11."
Thursday, October 01, 2015
OS X El Capitan Problems: 5 Things You Need to Know (Gotta Be Mobile)
El Capitan is working well for me so far, on my ~ancient (early 2012) MacBook Air, although Mac Office 2016 is having issues; if you use Office 2016 and don't have Parallels + Windows Office handy, you should probably wait a few days before upgrading to El Capitan. Check the full Gotta Be Mobile post for more links and details.