After wearing it walking along the street last night. I got the distinct impression THE L2 has a larger sound stage than the L1. Often it sounded like the sounds were coming from a source outside the headphones. I rarely got this feeling with the L1.
I'll get my L1s off my daughter tomorrow and see if I can get the loose/broken cable to work. Then I'll try and do some A/B comparisons at that time with some different sources.
It'll be a strictly IMHO affair though so be warned.
As for now I'll say I think the L2 is definitely an improvement over the L1 (in both construct and smart design). Though I still like look of the headband of the L1 more (personal thing). Sonically it seems a little better (judging from my memory of the L1) but not so much better that I'm falling over the floor about it.
One thing the L2 does well is put a smile on your face and get you into the music. I guess that would be defined as "fun". Personally that's what I want in portable headphones. That said I don't have (I think) golden ears. I'm not able to isolate treble roll off or what have you. I just know the sound I like.
I'll let you know how much louder they can go soon too.