Well, I compared it to the HD650, and with a good amp LCD2 tightens up, but HD650 does not scale any higher from a "decent" amp so with my Beta 22, the LCD2 sounded noticibly better, but by a small margin, what was more significant was the size of the sound. LCD sounded bigger of course.
I would say that I've found just the opposite. For me, the lcd2 is almost amp agnostic...sounding about the same from most amps. But the hd650 has impressive scale. Going from the lyr to BHC is just jaw dropping.