Have you been able to drill down to see which processes are responsible for using the most CPU during these spikes?
Unfortunately could not identify a process that is causing this kind of strange peaks.
We recomposed now our POOL and set each Linked Clone to 4GB of vRAM as this was advised by VMware support.
No we are monitoring if this issue will occur again.
I would also suggest using 4GB of mem when using 2vCPU's but still. If a user starts to print anything and CPU goes balistic my guess is memory wont help you out.
It would be best to get a view of the desktop at the time when it is using high CPU to see what process is causing this. It could well be that the PDF printer driver is corrupt and is causing this.