I wish they all could sound the same(as long as it was good),if you've owned enough gear you'll know there are many factors in"good sound".It's no accident and its not "standards"its the mfr.design/process and quality of parts used that make the sound.I've personally never heard two prepro or avr units that sounded the same,even from the same company when at different price levels.

You'll never know what a good amp sounds like without a decent pre/pro(even if its one in a avr),but they are not created equal,all imo.