...any objective assessment of the characteristics of the product itself.But here's the problem. You can have a mental checklist of things you want the component to do, and how well it does each one of them. But the response to music is at least 50% emotional, which means that a large subjective element is going to come into the evaluation.
The trick is to keep separate the emotions inspired in you by the music played by the component, and other emotions you might have about the company, the advertising, the attitude of the dealer, and a host of other factors.