Reading DMARC reports it's pretty interesting to see just how often spammers attempt to use others' domains. The forensic reports should show the full contents of what they attempted to send, IIRC.
Doing some reading, it looks like configuring RUA will send an aggregate like you mention, while configuring RUF (F for forensic) will give more granular details.
... in theory. In practice, I don't think any major provider actually sends RUF reports.
It would be nice, to see what exactly the people are sending who are trying to impersonate you. Though my hunch is that it's deemed a potential security risk. Instead I rely on bounce messages from invalid addresses spammers are trying to send to, to show me what they were trying to send. It's rarely ever anything too exciting.
Forensics reports would be nice indeed, but even Google doesn't send them to the RUF address. Never got one report in 4 years of DMARC. Only RUA. Maybe one day..