After a few months listening and tesing with the SM, I must say this is an increadible piece of equipment and would like to give here some (positive) feedback.
Initially bought to enhance the sound of my Swisscom TV receiver box and for movie playback, I now feel I can use it as a main source for my pure audio listening sessions as well!
In my setup, I get a virtually identical sound quality as with my Win7 Jplay-v5 driven (the best one I found on Windows with ASIO driver now supporting song-seek and volume control, initially using the now relatively less convincing foobar0.8.3 on XP in unmapped mode) and Paul Hynes SR3-12 powered USB Off-Ramp (older but still gorgeous version Turbo 2 with SuperClock 4 upgrade) feeding my Empirical Audio modded Northstar Design m192 DAC through a Revelation Audio I2S silver cable.
It is noteworthy to mention that in order to get there I had to power the SM (standard 96kHz version with 24bit setting) with a Paul Hynes SR3-12 power supply and use a high performance SPDIF coax cable (found a fantastic 1.5m silver reference cable BNC-RCA from less-known CableDyne company at a very humble price tag). Both of these upgrades are absolutely necessary in my experience to really let the music shine through the SM (and totally forget about any technical audio aspects). Leave one of these two out and I would just go back to my OR-2 setup for ultimate enjoyment.
The rest of my audio chain is Empirical Audio Holophonic analog RCA cables (no longer in production) to a Vecteur Club Twelve MOS-FET amp (upgraded audio fuse and home-made solid wire power cord) and EA Clarity7 speaker cables (no longer in production) to a pair of B&W 3-way floorstanders.
From a usability point of view, the fact that I can simply connect my small fanless nettop PC running XBMC (latest v.12 frodo for ultimate functionality and content including SpotiMC add-on for Spotify streaming) through a simple HDMI cable, as well as my TV set-top box and other multimedia devices using HDMI cables to my Philips LED-LCD-TV, select the input on my TV and simply use an optical-SPDIF cable from TV to SM without any sound degradation compared to a straight optical out from my i7-MacBook Pro running Win7 Foobar to SM, this is an absolute killer!!
Thank you so much Steve for making this (as we would say here) "tour de force" possible!