Dear Audiophile 1, my experience requesting firmware update from Mcintosh it is not a assessment it is a fact after exchanging 9 mails with customer support never had straight answer until I asked them is there firmware update for D150 or not ! eventually answer was yes there is but we can not provide you because of reasons pointed out in my earlier comment also it is totally irrelevant that update does have a impact on sound they did not offer to do it nor advise me what to do .
contacted Mcintosh dealer who they checked their service guideline firmware update v1.02 is not been provide to them in short really gobsmacked I'm not one of those throw all my toys out of my pram but definitely off loading my Mcintosh mono amps & preamp /dac to replace it with another brand who they offer me infinite help and support when needed,in the past I own Krell, ARC, CODA ,PLINIUS , APOGEE products I 've had their technical support team directly contacted me without re directing to their dealers,, Thank you all for your comments.