Ok so I lied: Thunderbird isn't really any shinier, I
just thought that headline might make C.K. download it faster on his quest for a Mail replacement. But seriously, it sounds like they've
made some significant updates with RC2, when I thought release clients were simply about squashing bugs. Among the list of updates: better automatic updates,
spell checking as you type (how 'bout it Firefox??), redesigned options UI, improvements to podcasting and RSS, built-in
phishing detection and more. These sound like nice upgrades to an app that reportedly (and I agree) beats the pants off
of Mail in the IMAP department. Still, as Hawk Wings points out,
Thunderbird's inability to play well with lots of other OS X apps, lack of applescript support and just plain
"butt-ugly" UI can tarnish the Thunderbird experience for some OS X users.
Me? In my journey for Mail alternatives, I'm slowly settling into the Gmail way of things. It's certainly a new experience going from a desktop app to a web-app, especially for something as intensive as handling the army of email I collect in a day's time, but Gmail does most of the things that I was using Mail plugins for, such as MailTags. Plus, since Gmail went mobile, I don't necessarily need to keep my PowerBook glued to my head 24/7 to keep on top of things, so it's been working out so far.
At the end of the day though, it's nice to see another large choice in email clients besides Mail and *shudder* Entourage, especially since Thunderbird has a few unique tricks like RSS reading up its sleeve.