So I had this discussion yesterday..
Virtual Machines on a SSD: Yes or no? Good or Evil?

What's your opinion?

I keep the OS partition of my VMs on my SSD, because they are unusable otherwise. At least if it is a Windows vm.

There is nothing inherently good or evil with that. If you have enough SSD storage, sure, go for it, otherwise put that on a regular HDD.

PS: Never had any trouble with my VMs not working on one support or the other.

I run multiple VMs concurrently at home on a HDD, no issues.

I run multiple VMs concurrently at work on a SSD, still no issues.

I have no HDDs in my computer so I also store my VMs on SSDs

Well his point kinda was that this slowly kills the SSD because of the write cycles. Well, yes I've written many TB on my 250gb SSD, but the benefits are clear:my VMs are much smoother.
Oh and the SSDs are still too small for it.

But on my SSHD, the (windows) VMs are so slow that it really makes no fun to work with. Linux is OK there.. Maybe my VMware messes things up there.

And I have 170gb left on my SSD that I use for my work VMs. I do all my work in VMs, this way my host OS stays clean and smooth while I can discard/reset the VM at any time.

(it's a laptop)

SSD! Got HDD and SSD on my Work Notebook and VM on HDD ist much slower. If SSD dies ist will be replaced.

Been running Ubuntu VM on SSD for three years no troubles at all. But a windows VM is painfully slow :/

Definitely SSD of you have the space. I always run my linux vms on ssd but windows not :P