I, myself, don't appreciate a comment that only gives my replay a rating. I really don't care about ratings too much. What I like to see in a comment is someone going step by step through the replay, pointing out if the move was good or flawed. e.g. 'that spin into the kick was great, but you hit with your shin too much'. telling someone how to improve their replay is one of the best things you can do.

That's how I usually comment on replays, and that's how I would prefer to have my replays commented on.