Verify asset versions, file agreements, attach briefs. Every one is ready to run, and you can adjust it in plain language.
Spot unrequested copy and layout changes in revised proofs.
See whether the requested proof fix landed and what else changed, right in the review thread before you approve the revision.
Check revised page proofs against your earlier corrections.
See which requested edits made it into a revised proof and which still need work, right beside the files on your review item.