Pros: Super stylish, very comfortable, decent isolation, good sound quality
Cons: bassy (ymmv)
Couple things, I am an amateur audiophile at best and this is my first review so bear with me. My listening rig was my Sansa Fuze v2 Rockboxed [unamped] (I have a PA2v2 on the way so maybe I will edit this later on). Most of my files are all V0/320 MP3 and FLAC and include a lot of live recordings.
I bought these from Amazon Warehouse Deals in "like new" condition for $165. I am convinced these were never on a pair of ears before reaching me - or someone tried em out for 20 minutes and decided it wasn't for them. Seems like I lucked out on this one.
***PLEASE NOTE: The MS400 are right on the fence for being supra-aural or circumaural - for me they are circumaural and my ears fit inside the cups. This affects the majority of my review to some degree.
LOOKS: I think most will agree these are a modern, sexy set of cans. I have the all black version - the red just isn't me, too flashy for my tastes. The carbon fiber is just so unique ; very nice looking.
CONSTRUCTION: Meh, they feel a bit plasticky but I have a feeling they may be more sturdy than they let on. There is some resistance in the swivel and sometimes it feels like I am gonna break them if the cups are flipped but they seem alright. The cable is very skinny and some may not like it but I prefer it - I bought these with portability in mind. There are no microphonics before the split in the Y cable however you do get some noise above it (it's not bothersome, my RE0 drive me nuts even with a shirt clip - these are nothing). In the same breath, an angled jack would have been better - oh well, it's a low profile straight jack anyways.
COMFORT: So far I find these extremely comfortable. As I said, they are circumaural for me ( I have rather small ears) but I think for most they might be supraural. Besides the fact that they seem to get a little warm on the ears they are really comfy; for me they are the perfect size, weight and clamping force.
ISOLATION: Pretty good - on par with my SRH840 and maybe a little behind my RE0.
SOUND QUALITY: As I said, my ears fit inside of the cups so I probably have a different listening experience with the driver closer to my ear. Out of the box I was disappointed. The bass was boomy and drowning out the highs and mids - something I was afraid of (note: I am not a bass head - I enjoy controlled, defined, punchy bass). I just couldn't get into them, vocals were veiled - guitars were lack luster, bass was mushy etc.....After a couple days of listening at work (~8 hrs) and telling myself I must like a more forward sound (on the other hand my SR80i can be way too fatiguing for me at times), I brought them home for some pink noise burn in. I was just not enjoying them. I have been letting them burn in with pink noise for maybe 30 hrs and they have definitely changed (I don't care what burn-in skeptics say!). The bass has tightened up and is not as boomy - however, let it be known these are still a very bass heavy set of cans. Either as a result or independent transformations, the highs and mids are now much more prominent and detailed.
Listening to a very nice recording of a Jerry Garcia Band show (1978-03-10) outside this evening I was enjoying every minute of it. The bass was thumping, the drums were tight, Jerry's vocals were crisp and his guitar was singing ... really great PRaT. Even the female backing vocals and organ had opened up. I will say that everything feels a little recessed and in the back ground, possibly as a result of the bass being so prominent - I won't say "veiled" but you know what I mean... I can hear everything down to the softest cymbal hit to a quiet tambourine, however, they definitely don't have that shimmer of a Grado.
Sound stage is still a weird concept for me and hard to describe. They feel confined compared to the Shure SRH840 - which still feel like a closed can but a much larger space.
Would I recommend them? Yes, definitely. These are a great portable set of headphones - unfortunately I have not listened to the HD25-1 II, Beyers, or any other portables for that matter but I am definitely happy enough with them so far to not go trying those out . That may change but I think they are growing on me. If these really are the anti-Grado as some say, then I honestly think I prefer the Grado end of the spectrum but the sibilance and shrill highs really bother me sometimes... I could listen to the Phiatons all day long - no fatigue here. They may be bassy but they are smooth!
I will edit this after I listen with an amp/ try the Armaegis cotton mod.