I got to agree about the lack of "bounce" - I could never move my work email to gmail for that reason alone (not to mention my preference of writing emails in my native editor).
If B forwards it to C, the email appears to come from B. If B "bounces" it to C, the email appears to come from A.
(it's the Resent-to header in RFC 822 IIRC)
So say you get a bug report from A than you know only C can fix, by bouncing it to them they get to easily reply directly to A and get on with it, leaving you out of it...
Two caveats: 1) no meta key, which makes navigation less handy sometimes; 2) C-k will kill the line, but I haven't found a kill-ring and you can't use C-y to yank the line back! This has bitten me a couple of times.
It's definitely nothing close to having a full text editing Emacs widget, but I've found it handy.