OK, so after a few weeks playing in the ZVC4, I feel I can actually add something to this thread.
Yes, they do run half a size long, but if you need width up front for your toes, as I do, you may want to go with your normal size. They fit a little like football (aka, soccer) shoes, quite narrow in the tip. It's not so narrow that I can't deal with it, but if you're going to be irritated by pressure on the side of your big toe, it'll matter. Also, putting them on thanks to the one-side attached elastic tongue is a bit odd.
That said, they are rock solid stable once on, have good cushioning, and don't squeeze my high volume foot as awkwardly as the "straight-jacket" system Asics uses in the Gel Res 8 and 9. I'm really liking the support, fit, stability, and speed of the shoe. The durability probably goes without saying.