Welcome to the forum!
I don't know if this will shut him up, but here's my philosophy: It's
your system, and
you're happy - BAM, done.
Why care if he likes something else better? If you think that your system sounds great, then that's all that matters. HK makes good stuff. So does Yamaha. Hard to go wrong with either one.
Sorry if that doesn't give you the ammo that you were looking for, but it's what I'd tell him.
Adam