Hrm - I noticed when I tried to reply-to all (my client is actually google mail's web interface), that debian-user didn't even show up in my To: field. Strange.
However, I hate it when I accidentally reply-to the whole list when I meant to send it only to the sender. I think a mailing list post should be deliberate and conscious, not accidental, especially considering every thing we (mis)post is archived forever. Mistakes are correctible in one direction only. reply-to: list is completely counter-intuitive. I always use reply-to: all when I want to send a public message out, and I assume that when I just do a regular reply, it is going to the person who posted the message. Also, debian-user is has ENOUGH traffic as it is, so we don't need a whole lot of accidental posts on top of that. So my vote is NO.