I tried to update from 10.11.1 to 10.11.4 using the combo update, but during installation, I got an error saying something like the update could not be verified and that I needed to download the update from app store. The system restarted and gave me a notification about the problem with the update and asked me if I wanted to download the update from app store. I agreed, and it started downloading the 10.11.3 update. I installed that, restarted, and then downloaded and installed the 10.11.4 update.
After updating, I needed to reenable TRIM, but otherwise, everything seems to be working fine.