Dexcool is a high maintenance coolant.
It must be checked regularly to make sure the level in the bottle is maintained. It has a much higher evaporation rate than traditional "green".
Since Dexcool has no silicates in which to "plate" components with its anti corrosion properties, it must completely cover the items to continue to protect them. If it eveaporates down, and oxygen invades the system, than expect corrosion like you've never seen before.
Also, if by some strange reason , you want to continue using dex...make sure you swap to a replacement stant radiator cover. Donot continue using the oem design.
In short...IF you maintain the level in the overflow bottle, limit the dex to max of 3 years, and replace the oem rad cap, than dex may be alright.
Check out google when I did a search on dexcool.