Procalc, comparing equipment is a common technique employed in reviews. It's an important element that helps legitimize the reviewer's opinion of a product. Without such comparisons, a comment such as, "it outperforms every amplifier that I have heard under $20,000", carries no weight. It can be done without bad-mouthing any manufacturer by explaining how the Signature does things better than other amps.
I'm glad you have found an amp you enjoy, and it's good to know the Signature sounds better to you than the Reference.
I'm glad you have found an amp you enjoy, and it's good to know the Signature sounds better to you than the Reference.