He stated there was no room correction or DSP applied to the Naim when unboxed, so I presumed it had something and wasn't used. As for the Lyngdorf, if nobody listens to it "as is" in a familiar environment, how will anyone know what it really sounds like, or compares to anything else? The product has to sound good before messing about with DSP, otherwise there's no point polishing the proverbial...
You're a dealer, I would expect you to have more knowledge than me. I will repeat 2 facts again. In the manual, Lyngdorf explicitly and strongly recommends the user to run the built-in, free room correction system. The Naim does not have any room correction facility.
So, in your esteemed wisdom, should the OP not have run the free Lyngdorf room correction to spite his face?