PS4 launch day, digital or disc?

I'm trying to work out if I want to pick up a physical disc on launch day (Watchdogs) or download the digital version. As far as I understand all launch titles will be available to download on day but will all titles support play as you download? Not sure I want to sit with a launch PS4 waiting for 50GB @ 5mbps! Will all games have demos? Will digital releases be more expensive than retail discs? (I doubt this, discs seem to be full rrp). Will disc releases have bonus content the digital versions don't?