I'm going to download and sync for update. The servers will inevitably be swamped tonight again so it's probably not worth the risk to do it over the air. I'm going to update tomorrow night instead. I'm travelling friday so I really want to try the 'sat nav' out
I usually find that, when a new update is released, downloading it via iTunes takes forever, but many sites post directly links to the IPSW files, which download at full speed, so I just do it that way.