I too purchased the Dolby Access plugin right away after learning about it here. I'm running a 7.1 home theater ATM, but my twin subs and 4 Atmos speakers are currently enroute to transform it to 7.2.4 =D
I'll have my HT Atmos up and running around the first part of June. Completely stoked, can't wait!
Regarding the Dolby Access plugin for PC...I would absolutely use it while gaming or watching movies with headphones. For music, I'll likely leave it off. Now that I have it though, I'll leave it on for 2-3 days to get used to it.
Have only tried it for a couple songs so far, but I pretty much agree with your assessment. Highs seem to shrink, though it does seem to play with soundstage width and add some reverb. I think I AM getting more used to it the more songs I listen to with it enabled, and it's becoming more pleasing.
Of interesting note, I think that the larger the soundstage the headphone has to begin with, the greater the effect of the Dolby Access. M1060 received more spatial benefit than my Stax does (M1060 has a wider soundstage to start with). It IS a different flavor, but I've always put more stock into close-in detail and imaging than a wider soundstage; others may have different preferences for sure.
I only have M1060 and Stax 207 to test on presently. The rest of my headphone collection is being Bogarted by reviewers DMS3 and Zeos Pantera
I'll probably IM you to discuss Atmos HT
@CluckerByte Thanks for sharing the Atmos for Headphones info, I *am* glad I now have it to play around with.