X1xx/X2xx/X1/X1 Carbon with best outdoor screen?

[feklee]

Which ThinkPad in the X1xx series, X2xx series, or in the X1 / X1 Carbon series has the best outdoor viewable display?

I read that the X201 Tablet has a 400 nits display. Is that still the best? What about the X230/IPS?

Example usage scenario: Sitting on a sunny day in a street cafe under a parasol. So screen in the shadow, but pupils contracted due to bright surroundings.

[feklee]

Actually, I just found that the ThinkPad Helix, which has an X series form factor, has a 400 nits display. Only that display is minuscule, its area possibly taking up just around 50% of the laptop's lid area, the rest is plastics - pha!

Still when outside, brightness matters more than size, so I could possibly live with that. Only the Helix is going to be pricey.