I really like the improvements to the PM system, except for sent messages, where we’re pretty much back to this issue:
At the moment, messages display my avatar (maybe unnecessarily; it’s my sent box, after all), but do not display the recipient unless they reply. Most messages I send are moderation messages, where the vast majority go unanswered. So my “sent” box has hundreds of messages with only my avatar, and no easy way to distinguish one from another.
Recipient should always be shown for sent messages, IMHO, regardless of replies.