The LCD-4 may measure a bit lower in the treble region, but in some pretty punchy songs it very much is ready for the occasion.
It is no slouch, but still nowhere near the top of my list these days.
Yeah, it's not a "slow" laid back headphone like say the HD 650. When I said most laid back of the three, emphasis was on "of the three." The LCD-4's focus is very much on the mids and bottom end. It doesn't have the most extended treble ever, I heard it go up to 18 KHz or 19 KHz in a sweep test (I forget which). But it is definitely the least revealing of the three by very clear margins.
And you made a good point about the Abyss. Fit plays a huge role, so feel free to mark my impressions of it with an asterisk since I never owned one so didn't test it out while fitting it differently. The Phi is also much better than the original from what I gather... kinda crazy how the original was a $5,000+ planar with sub-bass rolloff like a dynamic headphone. And I believe the only difference with the CC vs the Phi is pads which you can get separately.