Mac OS X gets bumped to version 10.11.3, brings bug fixes and security updates
Apple on Tuesday released OS X El Capitan 10.11.3, a new point release that the company says brings bug fixes and security updates to the venerable desktop operating system.

There is no word yet on what specific changes Apple has made, but it figures to be a less wide-ranging update than OS X 10.11.2. That release brought improved Wi-Fi reliability, enhancements to Handoff and AirDrop, and fixes for problems with Mail and iCloud Photo Sharing.
Apple had previously provided developers with two beta releases of 10.10.3. The last preview dropped on Jan. 6.
OS X 10.11.3 is available now via the Updates tab of the Mac App Store.

There is no word yet on what specific changes Apple has made, but it figures to be a less wide-ranging update than OS X 10.11.2. That release brought improved Wi-Fi reliability, enhancements to Handoff and AirDrop, and fixes for problems with Mail and iCloud Photo Sharing.
Apple had previously provided developers with two beta releases of 10.10.3. The last preview dropped on Jan. 6.
OS X 10.11.3 is available now via the Updates tab of the Mac App Store.
Comments
I have a 2013 MacPro with two 30 inch Cinema displays and a Samsung 4K display. After installing 10.11.2 I began experiencing the above mentioned problem. I can confirm today that after installing 10.11.3 the problem no longer exists. I've tested it all afternoon and finally my 4K display wakes up from sleep mode along with both Cinema displays. Before the 10.11.3, once my system went to sleep, only my Cinema displays would wake up. I would have to restart my system in order to resume using my 4k display. What a pain that was!! This is a great update for me!!
My MBP is soooo old that's the last version of Venerable it would take.
Installed it on my newish MacBook. Interesting though, this is the first time that the low power of my Core M CPU showed itself. 15 minutes to install the update. Maybe 20. Not sure how long MBPs or Airs are taking. Just guessing– not as long as a MacBook.
I've never noticed any performance issues, at all, until now. I suppose a software update is as close as I come to being a "power user".