I used to work at a Harvey Norman store and handled all returns/repairs for everything from the computer department.
From a repair point of view, how the company is to deal with, etc.
I would have to say my vote is with TomTom.
They freeze alot but its easily fixed. The majority of TomTom problems can be fixed by using the reset button they have on them. Other GPS devices have their problems but they arent as easily fixed. Also TomTom's service is here in australia.
Go for TomTom, youll be better off.