If I may, I prefer to listen to my in-ears straight out of the box, simply because irrespective of whatever subtle improvements/refinements I hear post burn-in, there's never a night and day difference. For instance, the SM3 initially sounded dark and veiled to my ears, and even after burn-in, while the sound did in fact noticeably open up (at least to my ears), becoming slightly less veiled, there was no confusing that I was still listening to the SM3. Hence, while I've certainly come to notice subtle improvements throughout the burn-in process, what's
MUCH more important to me personally is allowing oneself to acclimate to the earphone's intended sound signature (or as some would call it, brain burn-in), which can take quite some time. The RE252 serves as a prime example in my case, which at first sounded much too neutral and analytical for my ears. Ask me now and it's among my top 5 universals, for that very reason. Slowly but surely, I grew accustomed to it's signature, and came to admire it's incredibly natural, raw, and neutral presentation. The same holds true for the ER4S, among others, since there are not very many in-ears that
me from the get go.
Back on topic. Yay, go IE8!
No but seriously, it's been far too long since I last listened to the IE8, and I may pay it yet another visit in the near future. Personally speaking, I'm still awaiting a (much needed) price drop.