My Z is boxed up too. The poor screen was the biggest reason. Compared to my last Sony Z and SZ the screen on my 2010 Z was a huge step down ... shadowy, poor viewing angle, grainy looking ... when the screen on a low-res 13" MBP looks better than the hi-res screen on the Sony Z there's something seriously wrong. The Sony track pad also played a role in the decision after using the large / smart track pad of the mac's it's hard to go backwards.
So, my quest for a 'really good' 3lb full featured ultra portable machine ends unsuccessfully ... I've tried the Lenovo x301 the screen in it was worse than the Sony and track pad not much better ... Dells ... after my experience with that company it's not an option.
What's left? Who makes an full featured ultra portable that's decent?
I think the best option for a thin / light computer right now is the 13" MBP and it fails because it's 1.5lbs heavier - BUT - I would much rather have the screen, keyboard, trackpad of the 13" MBP and carry the extra 1.5lbs than I would have any of the (disappointing) ultra portables on the market right now.
We NEED a MAJOR upgrade to the MacBook Air, wouldn't an upgraded MacBook be great, especially if they offered both a 13 and 15" model ... we can dream