PHEW! Lots of replies!
First off, a DAMN YOU to Frostychrist for making me have to listen to Ghost Reveries again. I have so much new music to listen to, and now you made me go back to this! Holy christ I love this album. Unfortunately, listening to it with my PC as a source continues to show just how lousy the DAC in my H120 is in comparison. I'd listened to Ghost Reveries with the H120->Tomahawk->Atrio setup during a couple workouts, and the soundstage was completely flat compared to the ThinkCentre->Tomahawk->Atrio combo I'm listening to now.
Also, yes, the H1xx series is guilty of having a lot of hiss with low impedance IEMs. So frustrating! I can't wait until my builder has finished the Altoid-tin Monica 2 I commissioned (more details on that if/when he completes it)!!! Turn off the bass boost with the Atrios, though! You need to listen with a flat EQ. Bass boost with sound like crap. Future Sonics earphones are designed for improved bass response. Enhancements in the source will sound awful.
Jesus, Ghost Reveries sounds amazing. Damn you Frosty! I've got brand new Devin Townsend, Dimmu Borgir, Porcupine Tree, Blackfield, Threshold, Symphony X, Kamelot, Rush, and Tori Amos to get through, and I'm stuck back on an album from 2005! You suck!

BTW, Pain of Salvation's most recent album, Scarsick (which is a frustrating anti-capitalism tirade that slags the U.S. mercilessly and somewhat deservedly, and with a sad lack of class), sound absolutely AMAZING with the PC setup I detailed above. The soundstaging is phenomenal. I'd been rather disappointed with the material on this album, but listening with the Atrio and a better source has revealed an amazingly well-produced/mixed album. Worth hearing for the soundstaging alone, even if you don't agree with the politics, or at least with how they're presented.
I too have found that comfort, seal, and microphonics issues are all GREATLY improved when wearing the Atrio over the ear. There was a picture posted by mho in this thread (
have a look here) that shows the best way to do it. I wore them down, and yeah, I had microphonics issues. Also, the seal was kinda mediocre. Over-the-ear, with the memory wire bent into a hook over the top of my ear, makes for a very comfortable and far more effective listening experience. The seal is better, the tube is positioned better in my ear canal, and the microphonics are GONE. It seems weird since the curve of the earpieces goes in what seems like the wrong direction, but somehow it just works. Much more comfortable.
Lastly, I cannot stress the usefulness of burn-in with these earphones enough. If you read back, I felt the bass was a bit much, and the highs were uncomfortably bright, with the mids being recessed. Burn-in evens everything out and while the highs are still detailed, they aren't bright anymore. It's still disconcerting sometimes to hear sounds from these IEMs that seem like they're OUTSIDE of my head, but that's the beauty of these. Brilliant.
Thanks for the ER4 vs. Atrio comparison, tstarn06. Can't say I'm at all surprised by the results, but it's nice to read actual experiences rather than falling back on my assumptions.

Love it. Extremely pleased with my purchase.