Long battery life
Accepts external memory
Easy to use interface
Works well in light
Small screen (which is also why the battery life is pretty good) give one take another.
Price is a little high if you ask me.
Overall I found that no GPS is perfect and the technology itself has a long way to go. Each person will have different ideas on what is crtical for them to make a purchase.
I reviewed the entire thing at http://borbon.us/wp/?p=173