Tell you what I happens to me occasionally while listening to the upgraded MDAC - I would find myself glancing across the room because I heard something coming from some hidden corner of the room... only to realise its on the recording - such is the sound stage on the upgraded MDAC...
I don't want to put words in your mouth - but I guess your reservations concern the "loss" of Bass - despite now being deeper and more controlled?
Despite the vices of the standard MDAC, its "Fuller & fatter" body is better then being too lean....
However, after listening to the upgraded unit, I find the standard MDAC congested and "clumpy"... preferring the upgraded unit despite my reservations about its Bass "Body"...
I found that with the "DC input" modified units the Bass becomes "seismic" its the missing part of the puzzle... It really impressive, does not take anything away, just adds the Bass weight - without overhang or clouding the music - like a good sub-woofer should do...
MPAX is desperately need - and I'm glad as I've always had concerns about a GBP400 unit - if it would offer good valve for money, but after playing about with the updated units last week - I'm now very confident
I'm not in anyway saying the standard MDAC is bad, I'm just trying to improve a design that gets an awful lot right and at a relatively budget price (in our crazy non realistic world of HiFi)!
John