So I've been using DigitalFreak's earpad mod all day today and I'm finding it to be really, really comfortable. The tips of my ear no longer touch the driver enclosure, even after an hour of use, so my ears no longer have to be pained when wearing them for extended periods.
The sound signature is changed a bit on the other hand. The lower-highs are less pronounced, treble extension is improved, the midrange is brought forward a tad bit, and the bass quantity is reduced, thus reducing the bass thump. As a whole, this creates a more balanced sound while in a quiet environment, but the missing quantity of bass may be problematic for some (I still find it very acceptable to listen to while on the bus).
I also A/B-ed the M-100's next to some of the headphones in a local Apple Store and I can assure you that the M-100 sounds [subjectively] better than all of the ones I tested (UE6000, UE4000, Beats Executive, Monster DNA, B&W P5, Sennheiser Amperior, Harman Kardon BT, Skullcandy Navigator). That being said, the DNA and the UE4000 are exceptionally good for the price, I think.
The M-100's had amongst the worst noise isolation for the headphones I tested though. On-ear headphones seemed to have a LOT of noise isolation in comparison.
Edited by miceblue - 11/8/12 at 1:31pm