Mcintosh customer support

Not sure I agree with your assessment. There are plenty of people around who can mess up a firmware update and end up with a brick. McIntosh is protecting their customers by not introducing this unnecessary risk. Besides you would most like gain nothing sonically from the update.

Did they offer the option of shipping the unit to them to have them do the update?  Or alternatively allow you to bring it to an authorized dealer to have them do it for a fee?

I agree with both of the above comments and the question. Did they offer to do it for you or have a dealer do it? It sounds like their reason was valid for their protection and the protection of their customers.

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.