I have done some research on the Garmin Colorado GPS receivers as compared to the GPSMap 60CSx and reached these conclusions.
Pros:
- The screen is larger and higher resolution
- The controls are simpler and more intuitive
- The control placement above the screen seems better for one-handed operation
- Slightly smaller
- Uses regular SD cards instead of Micro SD
Cons:
- Shorter battery life
- Slightly heavier
- Expensive!
- Some negative user feedback concerning accuracy and sensitivity
Beyond the pros and cons, I realized that the GPS receiver's biggest shortcoming for Great Wall usage is the lack of a good topographical map incuding the Great Wall. This limitation would apply to all Garmin GPS receivers. Therefore I have decided that the Garmin Colorado units don't have much to offer over the GPSMap 60CSx, and so for now I will not be getting one.