I personally like Garmin XT, and have been using it for almost 2 years now. Tom Tom always did some rather unusual routing for me. It wouldn't get me where I wanted to go sometimes, or was a little inacurate on telling me where I needed to turn. Not knocking those that use it, just in my experience Garmin is worlds better, runs much quicker, and runs exactly like a stand alone GPS unit. Only Garmin drawback is that it doesn't speak the street names, but I'm ok with "turn left in .1 miles" then "turn left now" as I approach.
The latest Garmin XT has a google search feature that will find just about anything you can think of that's near you, give you the phone number and auto-routing! There are alot of other great features like the fact it constantly (even during your active route) checks for traffic issues like backups, road closings, construction, etc, and will route around them if desired. And if you want to see how it works in person, head in to a store that has Garmin GPS units on display. The software is nearly identical, but better on the ppc version due to the internet connectivity.
The problem with Amaze, Google maps, Sprint NAV and the like, is that your maps are being downloaded in real time as you need them. Not a good thing if you drive where you are either getting only 1x data, or worse than that, little or no reception. No data = no maps to route. I guess that's ok if you never leave a metro area, but on a cross country trip you'll run into trouble.
With the commercial programs like Garmin and TomTom, the maps are loaded on your SD card, so they are very fast and smooth, and work perfectly regardless of wether or not you have good data signal. I have the entire US map set on my SD Card and it takes up about 1GB. Best part is, these programs are a one time fee and you'll get use of it on every pocket pc you own from time of purchase forward.
Just my two cents... or three... maybe four.
