I got the Dell XPS 13 (9343 model) from work, and first thing I did was wipe the disk, and install Ubuntu 14.04. I'm running the latest BIOS, A03.
I did alot of tinkering to get the laptop booting. I discovered that the laptop will not work with UEFI booting. You need to disable secureboot, and boot the install media as a legacy device. Then perform a usual installation.
Once you have installed Ubuntu, check what kernels you have available. For me, I had to boot the 3.16.0-30-generic kernel, as the 0.16.0-36-generic booted to a black screen.
You can either edit the grub configs yourself, or choose to install "Grub customizer" (https://launchpad.net/grub-customizer) to fix which version you boot.
Bonus info: I also had trouble with the touchpad (not able to click and hold, and right click was messed up), and letters going missing on the screen. I fixed touchpad by telling synaptics it's a clickpad, and I fixed the missing letters by setting intel to "uxa" accellation mode (slower, but works). Edit/add the xorg.conf file, and put the following in it:
/etc/xorg.conf
Section "InputClass"
Identifier "touchpad"
Driver "synaptics"
MatchIsTouchpad "on"
Option "ClickPad" "true"
EndSection
Section "Device"
Identifier "Intel Graphics"
Driver "intel"
Option "AccelMethod" "uxa"
EndSection
If you use sleep (ex. lid close/open) then you may encounter that touchpad is not working when the computer wakes up. To fix this add this file to /etc/pm/sleep.d/
20_fix-drivers-after-sleep
case "${1}" in
resume|thaw)
modprobe -r i2c_hid
modprobe i2c_hid
;;
esac
I got most of my help from this helpful blog post and various other sites i cannot recall... http://forthescience.org/blog/2015/03/20/installing_ubuntu_14_04_on_the_new_dell_xps_13/