The equipment is only as good as the user. I can guarantee that if there was a hidden install competition between "high end" and "low end" there wouldn't be a difference between the two so long as the installation and speakers were the same as well as the source+head unit.
The job of an amplifier is to amplify sound without adding any "signatures" or cues to the music that weren't already present from the source.
There's a man offering $1 million to the person who can correctly identify "high end" vs "low end" in an a/b comparison. Nobody has won in about 10 years now. Sony is typically junk but so are the mentalities that use them. As long as an amp sends good clean power and doesn't blow up you're good to go.