If you haven't been to Japan and seen the crazy electronics stores, here is a shot of my local Yodobashi Camera, or rather, a couple of shots of part of the headphone section, which covers about 20m of wall:
Those are the IEM cabinets alone! As far as I know, all can be demoed.
On the right are the expensive headphones, only some of which can be demoed. On the left is one of 4 racks of demo headphones plugged into a distributor. Thankfully in this store, the distributor is up top, so you can unplug the headphones and plug them into your iPod or whatever gear you brought with you.
In my case, it was my iPhone 4 and Pico Slim. I had my easily bored daughter with me, so as much as I wished to try all the latest IEMs, it was out of the question. I did manage, however, to spend a few minutes listening to the full-sized Shures, which I've been wanting to try for a long time. In the past, when I've tried a bunch of headphones in the store, the two that have always stuck out as the best were the Audio Technica ESW9s and ES10s. Everything else has sounded boring or tinny, except Denons, which have that excessive bass, sucked-out mid-range and annoying highs. Today, however, I was very pleased to find that the Shures were an exception to my usual experience, sounding absolutely fantastic out of the Slim. I should say here, I am sure that my brain has adapted to a more mid-forward presentation than I used to like, as Denons now sound awful to me, and the Audio-Technica house sound has become listenable, so consider that with my impressions. The Shure SH440s seemed to have an overall generally neutral presentation, that is, without any part of the spectrum over-emphasised. The bass is well present and punchy, without over-doing it. This both gave the depth to some of my favourite songs, as well as made them good with music such as Shpongle (though I didn't check the deep bass here, do note). The mids were very present, Norah Jones and Nina Simone coming through strongly and smoothly. The highs didn't seem to have any excessively strong peaks but are possibly a little soft, resulting in a smoother presentation, rather like the Bowers and Wilkins P5s, but without the wacky frequency response.
Looking at the graphs, we see:
Out of the Pico Slim, I didn't notice as much of a bass peak as shown here in the 840s, but I only had time to flick through a few very familiar songs and the amp used to generate the graphs above is considerably more powerful than that. However, my impression of the 440s being reasonably "flat" seems to bear some truth. That wild treble peak is at 9-10 kHz, so above just about anything that can cause irritation, such as sibilance. The dip in the upper-mids and treble tallies with my impressions. Ignoring that last peak and the bass roll-off, the SH-440s look somewhat similar to my LCD-2's frequency response, which goes some way towards my positive impressions as well.
However, importantly they don't sound like cheap cans and are Grado-easy to drive. I wish they had existed when I first joined Head-fi looking to replace my old MB Quart QP55Xs. They would have been perfect.