not yet - I've been keeping my eye out. I don't think we'll see a review until mid-late July; the card with the I/O drive is supposed to go on sale at the end of July, the card by itself will go on sale in Sept (as last I've heard). That may still change, though . . .
first, make sure you're running the game with the audio console in Game Mode; with a set of 5.1 headphones, first try running the game with the speaker configuration set to headphones, if that doesn't work, try 5.1 - I'm not sure which is the best way to set these up; then, under the CMSS-3D tab, make sure that 3D positioning is enabled, and make sure both filters are set to auto - if in 5.1 mode, set upmix mode to "stereo surround" and upmix to "auto" - then adjust the slider all the way to 1005 surround. Hit the test button - the playback should smoothly transition, without any major change from one speaker driver to the next.
with the subwoofer - I've found with headphones to that you usually can't have bass-boost turned up too far, even default settings tends to be way too much in many cases. In the audio console, go to your bass tab - if set for headphones, set bass boost level to 1db, and cutoff frequency to 30Hz; if set for 5.1, reduce bass redirection to 30Hz, and leave gain unchecked.
TBH - I'm kinda feeling my way through this with ya, I haven't had a chance to use 5.1 headsets, so I'm in the dark as to what is the best and optimal settings for them. I'm curious, how do the 5.1 headsets attach to the card? Is it just the one green mini-jack, or do you have the 3 jacks?
I've seen what you're talking about as well - I'm not sure if you're in the states or not, but everything I've seen online wants bulk orders . . . so that's outta range of us commoners