Lots of work still needed, but two major issues with the review component are:
1) I get an email every time a comment is made. So, if a client leaves 20 comments in a review, instead of one email with 20 comments, I get 20 emails. We all know why that's an issue. What about having a button in the review component that would submit them all at once, like a "Commit Review," or "Submit Review Comments" button of some sort. That would allow me to get a single email with all notes from a user.
2) Seems in the case of reviewing an image, rather than comments being listed in chronological order, perhaps top-to-bottom comments, based on location in the image, would make them more readable/followable. At least having the option to sort them in that manner would be great. Right now, if you're commenting at different places within the document, it just takes longer to figure out which comment is where, because also, the document pane doesn't just scroll automatically to the area corresponding with the comment.