Both. In looking at my mailbox I see some forensic reports from 163 and aggregate reports from everyone I mentioned plus Comcast, Emailsrvr, XS4ALL, and QQ.

I don't remember if I eventually turned off forensic reporting, but I do remember that LinkedIn and Facebook were particularly strong proponents of DMARC (and both were really good about accidentally load testing our infrastructure). Oh and one very large provider that actually gave us unredacted messages.

Boy am I glad GDPR is a thing these days.