A very interesting experiment, thanks for that. It seems that the sound is much brighther and clear with the external microphoes than with the Edirol mikes. I am not too convinced about the noise reduction. While it definitely results in less ambient noise, it seems to sound more constricted afterwards, and it's like I start hearing the noise of the keys hitting the keybed (or perhaps the fingers hitting the keys).
The reverb is way too much for my taste. The direct headphone recording sounds really digital and synthetic compared to the acoustic takes. Personally I would opt for the mikes, no noise reduction (unless there is a specific noise, but then it would be better to re-record), and a less drastic reverb.