Not sure if this has changed with more recent models, but I've had rather bad experiences with UX31.

Although the model number was the same, most of the European variants had a different, extraordinarily bad SSD, which slowed down to <1 MB/s if the file system was something like >70% full.

Other indicators of bad quality:

- keycap texts disappeared for the most used keyboard buttons after just a month's use

- crashed once every three days on average (hardware issues?)

- The fan makes a buzzing sound as it scrapes the bottom of the laptop casing

- The screen died after about a year of use (booting up makes the screen gradually turn completely white within 5 or 10 seconds)