What is meant exactly by the description 'more musical'?

Musical - it has to be an umbrella that covers a whole raft of performance parameters and requires they be within acceptable limits. I think pace, rhythm, and timing come under the musical umbrella but also tonality and timbre. Since it’s hard to describe a “shrill” or bright sounding product that causes listener fatigue as being musical, then high frequency performance is in there too. 
I agree with distortion but I think that’s more of a cause than a symptom.

Unfortunately I think each of us has our own set of these performance priorities that must be met before we consider something to be musical, hence as an adjective it isn’t a lot of use in relaying a performance measurement that can be understood by a community. It’s like saying “I’m pleased with it”.

@atmasphere Understood. The ‘distortion product’ isn’t responsible for shaping or determining all of the various parameters that must be satisfied for a product to be considered musical. I don’t think that you are saying that it is, please clarify.

@atmasphere Ok, got it. I will have to think more on this. Example, I’d considered PRAT a key component of ‘musicality’ but it would never have occurred to me that PRAT could be a function of an amp’s distortion product or signature.