Before the changes to the trust system, this would have been okay after a deal.
Now, however, positive feedback means more than that:
Old Positive - You trust this person or had a successful trade.
Neutral - Comments. Your rating will not affect this person's trust score.
Negative - You were scammed or you strongly believe that this person is a scammer.
New Positive - You think that this person is unlikely to scam anyone.
Neutral - Other comments.
Negative - You think that trading with this person is high-risk. You might also be able to add a flag.