The headroom crossfeed appears to yield a warmer sound. This is not a bad thing because it provides me with a means to soften some harsh sounding CDs.
I almost always listen to my headphones with crossfeed on. The soundstage sounds unnatural otherwise.
Some folks mentioned that the processing reduces the soundstage. While this is somewhat true, I feel that the effect is misstated. Headphones, because of their near-ear placement, tend to reproduce exaggerated soundstage. Crossfeed helps reduce this spatial exaggeration.
But then again everyone has a different approach to sonic nirvana. Some do it with crossfeed, others don't.
