It is just a suggestion, as the stand alone units are far more tough and water resistant than the 6700.

ppc- 6700 as a GPS
Cons:
- the screen is not very visible in direct sun light
- Battery life (if you use an app that can turn the screen of this isn't so bad)
- durability / water resistance, grip (it will not survive a whole lot)

Pros:
- color screen
- more robust software
- you can make calls, assuming you have signal
- you can take notes and other tasks out in the field