I totally concur. The extra amp power allowed the pro-inspired speaker systems go to "eleven". Also, putting that kind of power into the consumer-oriented towers would have triggered speaker-related distortion or worse. So yeah, we're talking exceptional power and dynamics and clarity, when big-boy speakers are properly matched with pro amplification.
I do think the Legacy towers and the LS6 pair could have been run at high levels with pro power, since they were being presented "full range". Those speakers were not designed to be pushed by a receiver and I feel they could have put on a comparable show.