I have used a PND for many years. I currently use a Navteq (in car), Tom Tom XXL 540t, Garmin C-580 and Motonav TN765t.
I find the Motonav TN765t the easiest and most reliable. Garmin is a simpleton (older) by comparison. Navteq (in car)is a royal pain and disables once the car is placed in drive. Tom Tom is fairly simple, awkward to mount but provides more accurate routing than Garmin (by my experience).
Garmin's routing (IMHO) has gone down hill in the last three years. It's like some clown in Sri Lanka is routing me thru Upstate New York and has no clue where the Interstates are. Motonav routing by my comparison is spot on and gives suitable and logical alternate routes. Motonav gives me the quick Interstate routes first and side state roads as alt's. Garmin has "fastest" and "shortest" settings but those settings have figured out neither. Must be the programmer from Mumbai doesn't really know.
I do not like the way Motorola provides a hard copy "Quick Guide" in the box but then buries a link in the hardcopy to download the much more informative Owners Manual. (It's a money thing with the Quick Guide)
So, if you don't read the Quick Guide, you are really sort of clueless beyond the basics. The OM clears up a lot of issues you read about in the reviews. Motorola CS looks arduous and burdensome but the documentation is fairly good once you get it all collected.
The breadcrumbs are well thought out when you stop and think about it. You just have to follow them and that is just not clear right up front. So, yes, Mildred, it's about being smart by reading.
Simpleton Garmins are intuitive but archaic by comparison, ie, if you want more than one address in the same town, you have to key in the town each and everytime you want another address in that same city.
Motonav brings it into the 21st century and keeps the city just add the new street address and it gives you the same city option. Great for weekly Broker's Caravans.
A very Inteligent GPS? Oh yeah, a new GPS for the intelligent traveller who wants to drive smarter at a fraction of the garmins cost.
Large screen, Simple controls, Acquires satellites quickly, Compact, Easy menus, Easy to read, Easy to set up