I have only used the PWCC vault, but I’ve had generally good experiences with them. Everything is archived relatively quickly, imaging has varying scan quality, but mostly ok. The only issues I’ve had come up are around valuation, sometimes I’ll have a card drop to $48 or so in their “market value” and they’ll charge me for it, even if it was above $50 when it was sent and their “market value” is disproven by a few eBay searches. I also like the opportunity to get an insured shipping label through PWCC, which I don’t know if PSA offers. Fulfillment has been quick and reliable every time I’ve needed to ship something.
You may want to check out this thread here, which talks about how the eBay Vault and Collectors Vault are combining, allowing you to sell on eBay direct from the new PSA/eBay vault. However, selling fees look pretty high. From everything I’ve heard about the eBay vault, it is garbage, and the PSA vault isn’t much better. Personally, I would not use the PSA/eBay vault at the moment until they get a bit more logistical skill on their side.