The essence of the Rebel is that it’s so overbuilt that it never needs to strain in real world use. It thereby delivers full, rich, transparent, high-quality Class A sound. The designers didn’t attempt to win a spec war, and thereby maximized its output quality.
My Lyr 3 is physically half the size the Rebel and delivers a lot more power (9 wpc / 16 ohms vs. 0.95 W / 32 ohms). However, the Lyr doesn’t deliver the staging or nuances or coherence of the Rebel, even when run on the LISST. The Lyr always comes across as a bit hot and sizzling soundwise.