The data will improve on the back end. I’ll tell you though, the vector based graphics are fast.
What I’m really not happy about, is how bad passbook is.
I live in a major metro area (DC), and I have no problems at all with the maps. I expect the problems people are seeing will be short-lived, and every new release has something people like to gripe and moan about (e.g., "antenna-gate"). What I found interesting, playing with turn-by-turn, was that some odd decisions (go off onto the local lanes only to get right back onto the express.... which I ignored) it was making in routing on Thursday morning were corrected by Friday morning. It does seem to be learning from usage patterns.
What Im really not happy about, is how bad passbook is.
Passbook should simply get an "incomplete", as no one will be able to tell how good or bad it is until we see enough 3rd party support to make it usable (or not, as the case may be). I was able to get Target to send me a digital coupon, but I'd like to be able to add my store loyalty cards (and my Sam's Club membership card), as that's where I'll get the most use out of it.