Agreed with the above (Bangraman). I've been championing these phones since I bought them about 3 weeks ago, and for what they are they seem perfect to me.
I needed a portable phone with good isolation, I used Ety 4P/S for 3 months for that purpose but in the end they weren't for me. With the iPod Ety's don't have enough bass for my tastes (even with a perfect seal). I bought the SR-71 to try an improve them but even then, and with bass boost EQ on, they just weren't warm enough for me: they made Les Paul guitars sound like Stratocasters (ie thin rather than full-bodied and warm).
For a while it seemed to me that there was no reasonable alternative, the Shure line seemed just as compromised sonically judging by what people were saying about them (rolled off highs, crazy bass in the E5). The only thing that was available was the custom IEM option, at anything around $600 to $900 - an amount that I hope never to have to pay for a headphone.
So when I found out about these I jumped on them, and they actually cost me £40 less than the Ety's had cost me to import from the US, I got the Senns from a bog-standard shop in London.
They're not the final word in transparency and fidelity, but as portable phones they're excellent. They isolate well enough to use on the underground (and believe me the Victoria Line is very noisy), and in my opinion they are actually better for this than the Etymotic phones were. The Ety's had so little bass that using them in noisy environments demolished any sign of bottom end, making them shrill. Using them on an airplane was a waste of time, even with major EQ. With the Senns the bass is much stronger, so they still sound balanced in noisy environments and are much nicer to listen to in these circumstances, even though they isolate slightly less.
Sound-wise I am very pleased: great bass, balanced tonal range IMO (I don't hear excessive bass or recessed highs), punchy and exciting and they make music fun to listen to. They are reasonably forgiving of bad or old recordings (my Ety's really punished me if something from the sixties appeared in my playlist) and don't suffer from any sibilance (again the Ety's were unforgiving here).
The bad points are total lack of soundstage and comfort, I can't wear them for more than an hour without needing to give my ears a break, otherwise they start aching from the pressure. I could wear my Ety's all day if I wanted to.
All in all I don't think there is anything else that is portable, isolating and as good sounding as these for £130, which is their price new in the UK.