Took you a while to realize you turned out right
Nooooo, merely comfortable in that knowledge
In all seriousness your experiences with this piece of equipment does rather reinforce the tenant that a less than stellar demo of a piece of equipment, in a unfamiliar system, may not always form a true and accurate reflection of its capabilities.
With regard to the slight hard edge you mention, that might well be exacerbated by an impedance miss match or hook up wire however what you describe is IMHO a sonic trait of the factory supplied Sovtek 6550.