I'm in the market for a new one now. Are Thinkpad T/P series still the best for running Linux? How about the Dell XPS series which seem to have a better resolution and screen?
I've been running an XPS 13 (with the high DPI screen) for the last 2¾ years as my Linux daily driver, replacing the X230 I had before it. No complaints; I'd recommend it if the 13" ultrabook form factor is what you're looking for.
