If you're just doing a pet project to squeeze as much performance out of a Cmoy headphone amp as you can, that can be fun on its own. Testing out some higher performance solder and transistors, I'm sure the head-fi forum you mentioned in your post will have some interesting recipies.
The real advantage to Cmoy is low cost and portability. If you do your head-fi listening stationary (like me) and have a bit of budget to play with you have
a bit more leeway. I use this tube headphone amp at my desk at work and love it with Grado Labs headphones. I use my iPod but also have a Pioneer universal DVD player (563A) that lets me pop in CDs or even DVD audio/sacd. Although usually I'm using the iPod with 320 bit AAC and Apple Lossless files.