I love mine. Don't know about the earlier pre-production models but the one I have exhibits only a slight "closed chamber" soundstage, what I mean by that is that you will immediately notice you're listening to a closed headphone if you came from living with a great open one like I did, or you compare side by side. It is, imho, not distracting once you get used to it. That is a huge praise for a closed can, as I've never heard one I even really liked before.
But just like Tyll put it, with the foam inserts these are darn well balanced with controlled bass and no immediate annoyances anywhere even as you go up in the treble. Just a very nice, "right" sounding headphone that also happens to be really solid and lighweight.
It doesn't resolve quite like my STAX but because it isolates well, it brings out details in low-level ambient noise that would easily be obscured with the STAX. It's nice to sit on the balcony in the summer and get some sweet tunes.
Not that we get much of summer in Sweden...