TweetDeck vs. Spaz

I've spent part of the day witih TweetDeck after weeks with Spaz, and have come away with some comparative notes.

Spaz

• Simple tabbed single-column layout.
  
• Works well with the keyboard, allows you to scroll up and down, lightly greys items you've previously looked at.
• Scrolls pretty smoothly.

TweetDeck

• Single or multi-column layout.
• Multi-column layout looks a little lame when most of the columns are empty.
• It's nice to be able to separate replies from the rest of your incoming messages.
• The ability to group people or have a few searches up at once seems handy, although I didn't use either, and I'm not sure how often I would.
• Feels jumpy when scrolling, easy to lose your place.
• Not well-suited to keyboard scrolling and difficult to know which items you've already read.

Basically, these are both reasonable clients with different strengths; if you need to organize your tweets, I imagine TweetDeck is your choice.  If Spaz' simple layout will work for you, I find it a little more usable right now.

I've also played briefly with twhirl, but so briefly that I don't really feel qualified to comment.  I found the skin to be more noisy and cluttered, so I quickly went back to Spaz.