Manufacturers with great customer service

Aurender has been awesome. Replaced a bad LCD screen on my N100C at no cost and it was out of warranty.  They have been great with software updates and remote diagnostics.  Nothing but good experiences with Aurender. 
 

KEF, Both before and after sale. 

HSU Research. Had a plate amp fail after warranty. Although it wasn't free. they did send me a new amp for about half price.

OOPS! 

To my previously posted list - Bryston, Dynaudio, SVS, Woo Audio - I neglected to include Sophia Electric.

Sorry. 

Monitor Audio.  I wrote about this before, but I have (now vintage) 2 way micro towers (very small footprint) that I damaged.  Between my e-mail and woofers being at my door was 3-4 days. 

I was honestly sure they were going to tell me they were too old to have parts for. 

When I reached out to Spendor (A7s) inquiring about my room specs and potential integrated amplifier, they sent me a timely reply with some useful information and context, so thumbs up for Spendor.

Also, I wrote to Cambridge Audio regarding a question about the EQ in the StreamMagic app and they replied immediately with a helpful answer.   So, another vote for Cambridge Audio.