It's time to stop putting off that conversation you've been dreading. If you feel like sharing your thoughts about someone with someone, then do it honestly. The critical things you have to say are just as valuable as the positive ones (if not more so). Just remember to be tactful and use your diplomacy skills to deliver your message without hurting anyone's feelings. It will feel good to get everything out into the open. It's a valuable way to show this person you ultimately respect them.