Close to 30 hours burn-in on these. Have noticed just some very minor differences, treble opened up a bit. Bass is still pretty much the same.
Some rudimentary comments. First off, I get a perfect fit with these. Well near-perfect, deep and flush, great seal. No problems with the shouty-mids, in fact, i think it's a characteristic that makes them unique and special, but I can understand why people might not like it or not be use to it. Actually I quite love it.
I think even more so than the SM3, these require a good amount of "head" burn-in. Initially and now, there is that "speakerbox" effect some have mentioned. After a few songs, it does ease away, but a bit of it is always present due to the pronounce characteristic of the mids. The presentation is unique, I like it. Fairly wide and tall, mids crescendo up and "vaporize" nicely. Very mid- centric, good seperation. Highs are there, bit overshadowed by the mids. Bass is there, good sub-bass; however, those who have said these have a lot of bass, I don't get that impression yet, so hoping it will open up a bit more w/ longer burn in.
I loved these the first night, but wanted to wait after the new toy syndrome wore off a bit and let some burn in take place. Overall I like them, a cleaner-drier SM3 is not quite a completely accurate description, but I can see some of the relations. The presentation is very enveloping with some of the behind the ears feeling and combined with their sound traits, these sound very "ethereal" if that makes any sense, if I had to sum it up in a one word description.
I did do a quick A/B/C comparo against the FX700 and SM3, using a pop track, and while these are ASG-1 are nice, I still feel the SM3 clearly does everything better, sans seperation.-it's such a velvety smooth monitor and sounds more musical. Off the top of my head rank: SM3>FX700>ASG-1 at this point, based on my current preferences.