I have recently picked up the Momentum and Fidelio L1's, so been doing a bit of A-B testing. I have posted my thoughts here: http://www.head-fi.org/t/690018/momentum-sound-with-more-bass.
I am enjoying these headphones. Whilst they aren't the most engaging or detailed I find myself going back to them more than the Momentum's. It must be that warm lush bass.
I will look forward to hearing the L2's. I've heard some good things about them so far.