can you run reports for notes & attachments?
you cannot run a report in salesforce for notes and attachments, however, you can do an export from the data loader on either Attachment or Note.
You will need to check the "Show All Salesforce Objects" checkbox to see the Attachment and Note objects.
You can them filter by Owner and a few other values.
Hope this helps!
Can you please advise if it's possible to create such report on Opportunities & related attachments?
As I understand the current release had more to do with attachments used in Chatter.
Please refer the below link, it will help your to find a resolution.