Out of curiosity: what type of UDG case do you use? I don’t see a case that is flat.
And thanks for your long comparison to the Sennheisers. I have the K550 and while I enjoy them, I agree they are not an all-round solution. I find I grab my D2000s for electronic guitar (rock) music but prefer the K550s for acoustic (singer-songwriter) music. And I still find it strange that a few prominent professional reviews, that came out just after the release of the AKGs, claimed they did not need burn-in but most comprehensive reviews by true enthusiasts find they do. Personally -- as a music enjoyer just starting to appreciate head-fi -- I feel they do indeed get better (more settled) with use.