Hi Seb,
This is indeed a helpful answer.
We use personal management, but also redirect some files like the OST file for Outlook. I don't find Outlook is performing well right now. It takes one to two minutes until it is ready to write the first e-mail.We use also linked clones which shares an image. It's a good thing in terms of saving space.
I just think if the personas and the redirect files lies on a SSD disk and also the shared image one might see the difference. If that is not certain then I wouldn't opt for SSD.
Overall I think the new storage even with SAS drives will be speedier anyway. It's also a good opportunity to use the new caching technology of View.