I have a UX31A and my experience is like yours with Ubuntu 14.04.
Only quirk I have with the touchpad is that on Windows, with 1 finger idle on the touchpad and another finger moving the cursor would still move with the moving finger. On Ubuntu, the cursor remains stationary any time there are two fingers on it. I probably would not have noticed it if I weren't already so used to the Windows functionality so it isn't a big deal at all.
Only quirk I have with the touchpad is that on Windows, with 1 finger idle on the touchpad and another finger moving the cursor would still move with the moving finger. On Ubuntu, the cursor remains stationary any time there are two fingers on it. I probably would not have noticed it if I weren't already so used to the Windows functionality so it isn't a big deal at all.