I get what you're saying. I did get the chance to try out a few different pairs of the emu cups with chan. The swirl ones were definitely warmer and wetter sounding while the striped ones were more tight, detailed and dry sounding. Small sample size and all, but it was a subtle, yet noticeable difference. It was a bigger difference to me than the difference between the rosewood and striped Ebony (all the rosewoods were cut across the grain, i.e. Striped). Rosewood and Ebony are fairly similar woods though in density, hardness and resonance.
This is also a fairly well known concept in acoustic instrument design. Though it makes a MUCH bigger difference with instruments than in headphones, which obviously resonate less than a violin.
I think my bigger point is simply that I worry that based on your review (through no fault of your own, but you know how head-fi is) it will become Head-Fi dogma that the Fostex Ebony is tighter and dryer while the emu Ebony is warmer and looser. The EMU Ebony cups can vary a noticeable amount in sound, some sounding fairly close to Mahoganny and some sounding tighter and less resonant. My experience was it came down to if it was along, cross or quarter cut with the grain. (Along gives the swirls, cross gives the stripes, quarter gives a wave like appearance). Wood is always stronger perpendicular to the grain and thus you get less "flex" which leads to resonances, which can be euphonic, but can also obscure detail.