Ok - fair point, JLM. I'll supply what I can:
(1) The room size is 25-27 square meters (270-300 square feet) - almost a four-square shape - and has an open ceiling to our one and a half floor house. This means that the ceiling height is a bit shy of 6 meters/yards at it's highest and half that where the wall folds into the ceiling. To be fair, the room is part of an open floor plan towards the kitchen and dining room, but I do not think that will have much of an effect given the accoustics and shape of the open floor plan (off to the side at an angle and no open ceiling).
(2) In terms of listening position, I/we sit at about 2-3 meter (7-10 feet) from the speakers for serious listening, i.e. a bit behind the middle of the room, and another meter or so (3-5 feet) back for everyday situations. The positioning depends on the distance between the (bi-polar) speakers, and that depends on the actual equipment used otherwise and thus subject to change/adaptation.
(3) Unfortunately, I have no SPL measurement I can share, but as it's fairly easy to speak and be heard while my wife and I listen I would estimate somewhere in the 80-85 dB range for active listening. The room is not very dampened but does not feel like an 'echo room' either. It's on the livelier end of the scale for sure, which is how I like it as that helps the speakers to come alive.
(4) Music-wise, I'd say the serious listening is mostly to americana (country/bluegrass/folk-rock and all the off-shoots and in-betweens of this) with a healthy dose of accoustic instruments and strong presenced singers as well as jazz. Sure, I am a huge metal-head also but I almost never play that for the hi-fi experience and in fact mostly listen to such music with head-phones while working. I am in no way a bass-freak in the (no disrespect meant - this is an unfair generalization to help the illustration) American way but my speakers do have a very nice lower region as well - snappy and deep, rather than boomy. I appreciate a delicate and nuanced (or if you prefer to call this 'detailed') sound above anything else. I am very used to live music so accuracy in instrument and voice are key to me. I can live with compromises in regions as long as the overall result comes together as a whole, whatever that means to each of us, but in my case implies balance and soundscape. This is why the DDA reviews spoke to me above e.g. HAP/DAC/STA as the impressions I've seen are that the DDA is - when it works with the speakers - better at those two in particular. As many that prefer a more 'European' sound - and particularly those comming from a serious vinyl background - I have never had a problem with what many more 'American' ears (again - seriously no disrespect meant - we're all different in what we perceive as 'better' or 'more accurate') would view as a midrange that is 'too forward' or an 'overly detailed/analytic' sound.
Those of you that are into headphones might be helped a bit further if I say that I love my AKG K702 for instance, just as much as my Etymotics ER-4s (particularly with the HDP!), and clearly more than the also good HD650 (despite my heavy dose of metal music when listening to headphones and many classifying the HD650 as a better rock/jazz 'phone). I'm staying away from even trying the HD800 to make sure I don't 'have to have them' as I suspect that would be my reaction to them.
Finally, the Mirage 'si' model has a much better grip on the bass than the non-si has, but I still have to accept that the M5 and M1 are what made me move away from tubes in the first place. I didn't find a better price/performance way to get the bass to tighten up as much as I wanted otherwise. The rest of the range (for both the M5 and M1) was brilliant with just a 25W tube amp though, but then again... class A is also a different animal.
