While I can't compare them, as I only have the L1, I can say that you can get the L1 for around $100-$125 on eBay, which is how I got my 'like new' pair. This auction for instance: http://www.ebay.com/itm/Philips-Fidelio-L1-Black-Headband-Headsets-/221471476412?pt=US_Radio_Comm_Headsets_Earpieces&hash=item3390ba8abc
From what I remember on the sound differences I had read about between the L1 and L2, the L1 has a bit more bass and the L2 is a bit more popular with the pure audiophiles due to it's more neutral sound signature. I remember people that didn't' like the L1 because it was too 'dark' liked the L2 more because it fixed that for them.
As a non-audiophile myself that likely would have trouble hearing the difference between the L1 and L2, I decided to save $200 and the wait for the L2's to become available in the US and went for the L1's, which I like a lot. The X1 I didn't really consider much at the time because I wanted a bit of bass in my headphones, and from what I understood at the time the X1 has less than the L1 due to the more open design.
In summation, I went for the L1 because it could be had for about $200 cheaper than the L2 and from the descriptions in reviews it sounded like I would probably enjoy the sound from them more than the L2 or X1, as I was looking for headphones that are fun to listen to as opposed to a more neutral experience to analyze my music. For more helpful opinions you may need to wait for someone with actual knowledge beyond what they read in reviews and forums, unlike myself.
Edited by wiski - 7/10/14 at 5:10am