Recently completed a job where we installed a 50" LG with a Sonos Playbar and sub- great, customer loves it.
This room was the primer for the coup de gra, 65" Sony 4K, custom Sonance soundbar, sub, Marantz 7705, 5 channel amp, Apple TV, cable box, blu ray player, Music Hall record player, RTI T2X.
This portion of the job took some time, getting the speaker made, a complication with the TV, time between other jobs.
Recently customer lost power as there was an issue with the sound, he made veiled intimations about the Sonos Playbar working better than the big system. I replaced the Marantz with an advanced replacement and reprogrammed everything. Guy was happy...ish
There is a recurring issue where the sound is getting dropped on espn and espn2. So I get a text last night saying he isn't happy and never has been with the system, basically is tempted to rip half of everything out and wants a Sonos Playbar instead.

Obviously there is a small issue with the sound, most likely the cable box- but it seems like a moot point to try and replace/fix if he just doesn't like the system.
He did sign off on everything and a lot of the system was custom, in my opinion - take out the soundbar, but tell him- it is yours?