tomscy2000's A/B comparison of the Ultimate Ears In-Ear Reference Monitor and the Noble Audio 4C clinches head-fi's role as the most complete source for all things headphone.
If you've not yet got a pot of coffee brewing, get one on. If you've yet to shave, don't. Tom's ~7.000-word essay goes better with a beard.
In-Depth Comparison: Ultimate Ears In-Ear Reference Monitor & Noble Audio 4C (Wizard Design)