Some time ago we were advised to reboot Space every month (when there was no update available that would forece a reboot) in order to make the system behave better.
Now that we're on 16.2R2, is this still required, or even recommended?
This is a Space instance running as VMs on ESXi 6 managing a dozen srx/ex devices.
If you facing performance issue, then it is better to open JTAC case to investigate further.
In addition to what PML said
I would suggest installling vmtools as it suported on16R2 version and monitor your system
I would also suggest to follow the juniper recommendation to have better performance