Hi all.
Just wanted to post my opinion on these phones since they are relatively new and not many seem to have them yet.
 
As a bit of back ground I am a long time Ety Er4 fan as well as shure e4 user. As I talked about here, I lost my e4s recently and ended up replacing them with both a set of shure 535's and also Monster Turbine pro coppers (such an expensive hobby we have...)
 
So to get to the point, I went on a three week business trip and somehow stupidly forgot to bring ANY phones with me. Couldn't be without my tunes so at my first layover I stopped in one  of the in-motion stores to see what they have.
 
So after considering buying one of the two models I already have or something else, I for cost reasons narrowed the candidates down to either the Klipsch S4i (which has some fans here) or the Shure 315s.  I ended up buying the shure 315's based on a brief A-B comparison in store with the thinking that I could at least sell them when i got back home with out getting killed
 
I liked the S4i design and iphone compatibility but found the sound lacking specifically, the bass was tubby and heavy and the very upper end was a bit harsh with music i like (specifically Roxy Music Avalon). 
 
So now that I have had the 315's for the duration of my trip, I came away very pleased when I ddi not expect to be. Basically the sound of the 315's is best described as a 535 light. What I mean by that is that the 315's seem to have the nice warm balanced sound of the 535's but without the very low and very high end
 
That sounds bad but what it really meant just a smidge less sparkle in the cymbals and just a little less bottom in the very lowest range (massive attacks Angel as a reference)
 
That being said they were good enough that i only really notice them in strict a-b comparison with my 535's.  This is miles better than what I remember about the E3s which is why I ended up with the shure e4s at the time.
 
So to wrap up, I think I might keep them as my travel phones. I like the look of them as well (got the clear version). The only real place that Shure cheaped out is the case is not nearly as nice as on my 535s'
 
Cheers!
 
edit: sources, ipod classic 160 GB, Iphone 4, ipod shuffle 4th gen, no amp.  (yes i like ipods)
 

Aren't the 535's supposed to have really forward mids already?  That makes the 315's sound like mids only and nothing else o.O

I would not call the 535's mids forward per se. They do sound "rounder" than my coppers and etys but for a lot of music that i listen to (acoustic folk and jazz) that's a plus, That applies to the 315's as well.
 
But maybe different ears, different tastes. my main point is that the 315s' are a lot of the 535's but for a lot less money

I really like the look of the black and hear good things about them including a decent size stage. I put in an offer on a pair but didn't get my price. The right tip modding and maybe some P-->S adapter action(like with the SE420/425) and these could be a real sleeper phone at the right price. Detachable cables are nice as well.

The black housing do look very sleek lol I have to admit. It's a shame they didn't it offer it for Shure's 425/535 =_=.