EDIT: See statement at bottom.
I guess I'll offer up my impressions. I should first be upfront in mentioning that most of the headphones I'm drawing reference to are ones I've previously owned, and thus comparing from memory. Second, those headphones are from varying price ranges and thus I'm evaluating the headphone from a perspective of experience, not a price competitive perspective.
First, the build quality seems quite good. It feels sturdy and the materials feel nice. The top of the headband is real leather, but of the harder variety. The underside of the headband and ear pads are pleather, but feel very soft and comfortable. Not as nice as the real leather on the Ed 8 but close. The headband adjust with nice snicks. It's light weight and comfortable. If I were to nit pick, I don't care for the exposed curly cables on the headphone.
Onto the sound:
As a whole, the headphone is euphonic, unoffensive, and a little laid back. It doesn't have any sonic attribute that particularly wows me though.
The bass is the L1's most prominent feature. It's not grossly exuberant, in that it neither obscures the mids and highs, nor is it overly impactful. It's tight and has decent texture, but it's more weighty. It's not as punchy as the HFI-780 or Ed 8. It's not as detailed as the LCD-2 was either.
The mids on the headphone come through the bass cleanly in general. They are presented neutrally as opposed to forward. I prefer my mids a little more forward. Females have nice vocal tone. Males have most of their lower tonal range intact, it's just not as resolute and lifelike as the LCD-2. The L1 best cans such the SRH940 and K701 on male vocals though.
The highs are smoother and less aggressive than my HFI-780 (far less than Grados). Maybe closer to the Ed 8, if not for the L1's bass. While the highs come through the bass and present good detail, if you eq the bass down, the highs are slightly more present than the mid range. In this regard I think the LCD-2 R1 is a little darker than the L1, yet the transparency of the LCD-2 allows for better detail.
As far as soundstage, it's not very wide. Less than the HFI-780 and SRH940. Maybe closer to the Ed 8. and also similar to the Ed 8 in terms of depth.
Overall, the L1 is NOT forward, aggressive, or punchy. It doesn't have the transparency or speed of an ortho. It doesn't have the airyness or soundstage of the HE-5LE or K701. It's an attractive headphone that presents music in a warm laid back albeit moderately detailed fashion.
Edit: After a few more days of concentrated listening, I have to concur there is a slight nasal quality to the vocals. I did a few days of listening on the L1 exclusively and then went back to the HFI-780. The HFI (which I've owned longer than any other headphone) sounded much clearer and more detailed. While the L1 offers great looks and comfort, I think it sonic signature was mainly a novelty to me and I'm going to return it.
I like share my impressions, but generally hate to compel or dissuade someone from purchasing a product. (Except the Dacport or HA160D, those I solidly recommend even though I no longer have them.)