I just received my GR07 today, been listening for the past ten minutes or so. My first impressions - I agree with pretty much everything joker and ClieOS have said about these earphones. This is the first time I've purchased something new since my Altec-Lansing iM716s over five years ago, so this may be affecting my view of them, but they truly sound like dynamic monitors in that they're balanced across the entire range, but still have "dynamic character" - natural timbre, a somewhat-wide soundstage, lots of air, and unfortunately a dynamic "slowness" that is just part of the character. Still, despite them being somewhat slow compared to my preferred BAs, the GR07s are doing quite nicely in their ears for now. The sibilance is surprisingly not a big problem, and I'm generally quite picky about my treble. Hopefully over the next couple hundred hours the diaphragm loosens up and speeds up as it has time to stretch. It currently sounds kind of "un-burnt-in". I'm looking forward to seeing how they progress.
My favorite part about the GR07s is that they don't have any quirks - the cable is AWESOME (supple, yet thick, relatively little microphonic character, just the right length and textured perfectly), the nozzles MOVE (they are so comfortable with the nozzle movement and soft cable... and the included ear guides are another plus, although I'll probably stick to my phonak guides), and they have a nice right-angle plug. VSonic included a very nice selection of accessories, as well - a carrying case, hard rubber ear guides, two sets of biflanges, three single flanges, and a set of Complys. If I had any beefs it would be that the Y-split is a little lower than I'd like, and there's no mic...