I am a new user and a big fan thus far but wanted to add one suggestion for consideration related to conversation threads.
If a user has conversation threads selected as a General e-mail setting, and a message which has been archived receives a new response, it seems to arrive as a single message in the inbox. Once archived, it joins the larger conversation and one can expand the thread to see the messages within it. However, I think it would be useful if the entire conversation was “dragged” back into the inbox, so that one could easily see that the new message was part of the larger conversation and also how many messages the conversation contained.