Just to counterbalance the discussion, I find quickgpsfix very helpful.
Tomtoms usually get a signal pretty quickly outdoors while standing still. However there's only one general direction out of my house, and I usually start driving before turning on and choosing my destination on the Tomotm.
Once the Tomtom is moving, it has a very difficult time getting a signal without quickgpsfix (if it's been more than 3-4 hours since it's last been on). With quickgpsfix it gets a signal in seconds no matter how fast/slow I'm moving.
The problem with quickgpsfix is that once every couple of months, Tomtom screws up the download, and gives a bad file. When that happens, you get a bad GPS location or no signal at all for a while until Tomtom can fix itself with the satellites.
Also, another hassle is that if you don't have a bluetooth model, you have to plug in every few days to download it. An expired quickgpsfix confuses the Tomtom just like a bad file does.
If you're not getting any downloads, its usually due to the previously mentioned "bad file". To fix it, wait a day or two until the bad file goes away, then in Manage my device, remove all quickgpsfix files from the computer and the Tomtom. Then go to Update my device and Tomtom should give you a new file.