Pros: speed of route corrections, map capability, size, bluetooth handsfree compatibility with some cell phones.
Cons: map update software utility, durability of touch screen
For actually giving directions and finding new addresses, the Tom Tom Go630 was actually quite good. It can quickly adapt when a turn is missed, and when the signal strength is good, it can set out a new route in a reasonable amount of time.
While the map updating software that comes with it can be a strong point, it is also one of its downfalls. It installs as a TSR program that stays in the background on your computer task bar. But the concern I have is that it is not user configurable in any way. It autostarts at system boot up and there is no way around it. Updated maps are important, but I don't need software standing by in memory waiting for me to check for updates once a month or so. (you can check daily, but why? roadways are not that dynamic)
Similarly the somewhat large touch screen is a nice feature, but also the unit's eventual downfall. Mine became erratic as the 1 year warranty ran out, and eventually got stuck permanently. Unfortunately there are no other user imput buttons on the device and it becomes unusable. There are a number of reports in the user forums of units with stuck input clicks on the right side of the touch screens, which Tom Tom attributes to bad software updates via the map update utility. However, none of the suggested remedies, (full resets, erase memory, etc) worked for more than 1 day or 1 trip.
If you already have Go630 or a similar Tom Tom model, leave it mounted in the car if you can, or at least avoid storing in a glove box or other place where it may end up resting on its front face and the touch screen. As extra insurance, avoid updating the unit software when you update the maps if you can. During the year that I used it, I did not come across a software update that added functionality that was missing or that fixed any particular problem.