My experience with Sonos is that they are ok at moderate volumes, but when cranked up there is a noticeable "midrange hole" due to the smiley shaped EQ curve. OTOH, I doubt the Energy TC is that much better to begin with, given their small size.
Can't help wondering because of your AVR heat issues: How loud do you listen? Get an SPL Meter like this
Or, (less precise) you can download a free SPL Meter app to your smartphone and find out.