I have a couple of theories on the 100 ohm / 200 ohm situation.
The 200 ohm version is essentially an LCD-4 B. Audeze spent years developing a cost-no-object best of the best planar magnetic driver that no doubt involved dozens and dozens of different designs before they settled on one that sounded good enough to carry such a massive price tag and assume position as the company's new world-beating flagship. They sold a few, they all started breaking and they thought "Oh crap, what can we do about this", so they went for the second best sounding but more reliable option and thought that hopefully the difference is small enough that people won't notice too much. I mean, after so much R&D, how else could they possibly make a driver that was not only just as good sounding, but now also infinitely more reliable, and put it into production and start selling it in only a matter of weeks, when it took them years to come up with the design that always breaks... The company had to do something to save face though. They couldn't very well just refund everyone, pull it from the shelves and go back to the drawing board.
That's option A. Pure speculation.
Option B is that the 200 ohm version sounds just fine and it's all in people's heads. People hear what they're told to hear. We can't help it. We are all human and subject to expectation bias whether we like it or not. The amount of people that say that they heard a dip or peak at x amount of khz because Tyll said that he heard a dip or peak at x amount of khz is suspiciously high to me. If everyone who auditioned this headphone went in completely fresh and had no preconceived ideas of what they would hear, I think the number of people that made that same comment about dips and peaks would be much smaller. Also, the least satisfied people are often the most vocal - especially when it comes to the internet, and if you could somehow do a poll of the number of people that were satisfied with their 200 ohm LCD-4 vs how many people want their 100 ohm versions back, it would likely paint the 200 ohm version in a different, more favorable light. I would also suspect that the number of dissatisfied people would be higher among those who do a lot of reading online...
Maybe a little of option A and a little of option B?
Anyway, now that everyone probably thinks I'm an ass, I'll see myself out.