True offline maps only come in dedicated GPS nav devices.
Waze us closer to google maps that Sygic.
In Sygic, the maps are preloaded so you don't need a data connection for loading them and it has quite a few POIs to do an offline search as well.
You will need a data connection for a good GPS lock (A-GPS) and google search for POIs which are not there in the preloaded maps.
Nope, Nokia Here and Maps support true offline maps as well.