no-one on this site would be able to tell the difference between the Rega and a Benchmark in a double-blind test.
Actually, I'll bet most of us couldn't yell the difference between either of those, the Topping, your receiver, my old Krell or Bryston amps, etc.
We had a member set up a test between a good SS amp and his old tube Dynaco...couldn't tell the difference once he matched levels and couldn't peek.
Unless you are operating outside of the operating limits (clipping), it is a lot tougher than most will want to recognize.
Welcome by the way...looks like you stumbled across the right place.