18.208 was a disaster for us. Pushed it out last night, came in today to many issues. Specifically, on-prem MS Exchange server had excessive timeouts and interrupted sessions. It would log ASP errors in the event log, and from the client side, OWA would frequently not work, time out, or give random errors. Outlook full application would time out/disconnect. Also noticed websites would time out, then eventually reconnect several times. For example, was downloading a script from GitHub and the webpage timed out, then reloaded, then downloaded 2-3 copies of the file we were trying to download. These were all on MX105s and 95s.
Also had issues with an MX75 after the 18.208 update where VOIP traffic was not working. Rolled back, issues gone.
I would NOT recommend this firmware at this time unless you are very closely monitoring everything - these are just the issues we found briefly using it.
BHC Resorts IT Department