Unfortunately I lived the same dilemma well, your points are exactly what I felt. Even though MailBird had a very good "hype" when I read about it using it is Just the opposite. It offers a whole bunch of new functions such as integration with apps but everything is Just a disaster. I mean it can do the basics so you have all your accounts in the same place but its interface and everything about it Just screams "move on".
WLM was excellent, but I would rather go with Outlook 2010 or nothing at all. I basically moved to checking my every email account manually, because I was very irritated with MB. Microsoft seems to be destroying its every good thing (OSs, e-mail interface, Messenger was killed) and so on.
Só yes, I would rather have Outlook 1000 times rather than MB.