Re: FortiOS 6.4.2 is out!
I've pushed it out on a 60E.
The immediate impact I have noticed is the drop in memory usage- 68% before upgrade (6.4.1) and 48% after upgrade (6.4.2). Smae config, similar number of sessions before and after.
There are a huge number of bug fixes and looks like improvements from the IPS engine as James_G suggests. So far looks like a good move forward.