These are indeed valid factors. The 009 has better technology for sure. The increased efficiency alone may be enough reason to prefer it. Also, I noticed that the 009 is far less sensitive to ear pad changes than the 007 Mk1. And it's easier to adjust to head, and more comfortable. And the sound is more neutral (the modded 007 Mk1 is still warmer and more euphonic).
I think it is safer to say that it was the 007 Mk1 which was held back because the ear pad. Even with the stock 009 earpads it sounds much more open, but then the small change in stuffing elevated it to a new level. It became more open for sure. The felt ring helped the treble, midrange and bass resolution. The sound stage layering IMO is on par with the modded 009 and better than the stock 009. The 009 has all the reasons to sound better, and perhaps it needs a more educated ear and precise measurements to tell which is objectively better. However, based on my auditive perception and a wide range of music I listen to, both the 009 and 007 Mk1 sound much better now, and are on about the same level of "enjoyability". Yes, there are small differences here or there, mainly coming from the different optimal stuffing, and in rest, to smaller extent, from structural differences. And when it comes to the subjective terms of musicality, I slightly prefer the modded 007 Mk1 overall, albeit I like many things with the 009 more. I am sure there would be people to keep both, but I am fine with the modded 007 Mk1.
Please note that I said that I have found the stock 007 Mk1 quite much inferior to the 009. But then the modded 009 is much better in my opinion than the stock one, especially in the bass (extension, resolution, resonance), in the deeper sound stage and in the clarity of tones.
I would advise adventurous 009 owners to try my mod, it will cost them about 5-6 euros for the wool felt pad, 15 euros for the Olfa circular cutter, and 10-30 minutes of work. It's hard for me to imagine someone won't like the results more than the original, but in that case the mod can be reversed. There is no better test than verifying the claims by independent parties.
For 007 Mk1 owners the situation is more complex, since a replacement 009 pad is needed, and even small changes in the carbon foam part have audible effects. I will start a thread with steps, exact dimensions, and pictures.
) coming from the 009. If the 007mk1 did not have this 10k peak, it would sound totally muffled and even more closed in like ... an old LCD2. 
