My initial thought about the Chomebook Pixel is exactly that it would be a good Linux machine. But with a maximum of 64GB storage, it'll never be my main machine, sadly.
The 13" Retina MacBook Pro [1] matches the wifi Pixel in almost every characteristic except the touch screen, and is just $200 more expensive for the model with 128GB storage. However, there's no LTE option. [1] http://www.apple.com/macbook-pro/specs-retina/
- faster CPU (i5 2.5 vs 1.8 GHz)
- double the RAM (8 vs 4 GB)
- bigger HD (as you say)
- wider aspect ratio (Pixel has 100 extra pixels along the bottom in an overall smaller package)
- a bit higher (1.9 vs 1.6 cm)
- a bit heavier (1.62 vs 1.52 kg)
- bigger battery and runtime (74 vs 59Wh, reportedly 7 vs 5 hours)
Overall, a lot to be said for the rMBP. Good to have options.