While Twitter clients come and go, as far back as I can remember the two biggest have been Tweetie and TweetDeck. The Big Blue Bird knows it, too: Tweetie was acquired in April 2010, its app becoming the official Twitter client, and whispers suggest TweetDeck is moving to the nest in a $40 to $50 million buyout. The addition of multiple windows in Twitter for Mac's latest update is quite reminiscent of the latter's software — and it's also pretty clear Twitter HQ could learn a thing or two from TweetDeck's designers. More thoughts after the break!

The biggest addition is multiple windows. Here's how it works: any window you're viewing can be duplicated into a separate window (found under Window > Open in New Window in the top bar, or more simply by pressing Shift + Cmd + T). The new pane will shift to the immediate right, with a nine-pixel or so space in between. Seeing as most of your new windows will come from the far left mainstay, you'll likely be manually moving every additional window beyond the second, which can be aggravating. The list's names on the top are hard to see, both because their longer format (@name/list) and because by merit of being separate windows much of the top bar real estate is lost to OS X's "traffic light" window buttons. (My lists currently show up with just two visible characters, e.g. "@ohnorosco/sh...").

Make no mistake, I'm happy to finally be able to view multiple Twitter lists, but the user experience could still use tweaking. It lies somewhere between the casual user who only reads the main feed and the power user who would dedicate an entire screen to lines and globs of 140-character messages. In either case, however, I'm not sure why someone would need to move separate panes around. If a handful of pixels helps to make the flood of information more readable, sure, but I'd like the option of locking all the windows together and killing those unnecessary red / yellow / green gels that block my list names from being readable.

The other UI changes are all quite nice, and indeed for the better. The top panel on each window now shows navigation progress, meaning you can jump back to previous panes effortlessly. Direct message conversations are now presented via a string of talk bubbles, which is much cleaner to read. The profile page, too, has been spruced up with the follow button now easy to find up top. Typing '@' prompts a list of followed names for autofilling. I still don't find any button on the bottom of the app to be at all useful, but if you disagree, there's now a dedicated "new tweet" button on the bottom left corner.

What's still missing from the OS X client? Twitter's in-browser experience is still better at navigating through conversations (the OS X app requires a rather unintuitive double-click and doesn't always even work). Retweet counts are not at all shown. If list management is there, I can't find it. Is it the best OS X client out there? I'd argue yes, but it's not perfect. TweetDeck has numerous faults, but the one thing it does right is multiple columns. If Twitter is on a quest to create one app that bests all others, to create a consistent user experience that serves a flagship to all app developers, it still has to find a way to merge the best (and eliminate the compromises) of its disparate desktop options.