Maybe you folks can help with that?

What am I looking for?
- Something Durable. I need something that will perform and keep on performing.
- Something lightweight. > 4 lbs need not apply.
- Long battery life is a must.
- Usability and reliability are more important to me than tech specs.
ATM, I'm looking at these two laptops:
1: Lenovo X220

(Click the image for a review)
pros: sturdy like nothing else (apparently), IPS LCD panel, nice keyboard, better CPU and bigger SSD than the other choice
cons: not super-thin, has a fan while the UX31 is silent, some reviews say the plastic is bendy
2: Asus UX31

(Click the image for a review)
pros: DROP DEAD GORGEOUS, super thin, better resolution (1600x900 vs 1366x768), new CPU
cons: New, so it's kinda untested, some people report issues with the trackpad
So, what do you guys think?