When reviewing suggested edits that have blocks of code that are long enough to scroll, I often find that I need to scroll up and down one side of the review to find a change, and then scroll the other side to try and match up where the user made an edit. Could we add the ability to have both scroll bars move in tandem, like: http://jsfiddle.net/j08691/5mUQH/embedded/result/. Maybe we could have a simple checkbox that enabled/disabled this functionality for those times when you don't want them synchronized.
(Here's a minor update to the above example that has the checkbox functionality I mentioned: http://jsfiddle.net/j08691/5mUQH/1/embedded/result/)