Assisted GPS is a legit GPS. It simply uses cell tower data to get an approximate fix on your location before using GPS timing to narrow it down.
If you've ever used a stand-alone GPS receiver, such as the first or second generation Garmin or Magellan units, those do indeed take a long time to start up: it could take 5-10 minutes to get a good GPS fix.
As to your TomTom, did it have a Canadian map base installed? Also, did you drive there with the TomTom turned on, or did you toss it in a suitcase and pull it out when you got there? These days, most portable GPS units use their last known fix to try to shorten the acquisition time, and if you move many miles from the place the GPS was shut down, it takes a long time to acquire a new fix. (The same thing happened the first time you turned it on, but you probably don't remember, because you were doing the other setup tasks for a first time user.)