I use a desktop with two 1080p displays (Mac Mini) for my home work machine, but I also travel extensively and work from the road 90% of the time. I’ve been a digital nomad since ’09, so laptop buying decisions can literally make or break my career.
I currently have two travel laptops. When I bought the first, I was completely thinking along the same lines as you: 13 inch Macbook Air, upgraded to an I7, upgraded to 8G of RAM (the maximum you can get in there; I’d have gone to 16 otherwise, like my desktop). It’s close to Macbook Pro performance in a lighter body with longer battery life. I’m typing this comment on it now.
The second is a Samsung Chromebook Plus. Which I bought as a backup laptop to replace another Chromebook, and now end up using about 4x as often as the Macbook.
Main reasons: *much* better display, decent battery life, the stylus + tablet mode turned out to be insanely useful for taking screenshots (I develop a lot of Drupal training materials) and annotating screenshots for requirements gathering / design consultations with clients, good keyboard, and *it can charge from a USB battery pack*.
Full review of how it held up in an incredibly hostile project environment here: http://nonprofitable.org/afghanistan-samsung-chromebook-plus/
It’s also a third of the price of my Macbook Air, and is much more disposable if it gets wet in a Calcutta monsoon or gets left behind during a Taliban attack in Kabul.