engine coolant

[simple]

My question is regarding GM's dex-cool antifreeze. I thought the whole idea behind dex-cool was because it lasts 5 years/150,000 miles. Although I would never go this high with it, I see one conventional/non-dex-cool antifreeze that says it will last 5 years/150,000 also. (company is prestone, with their all makes/all model formula) Does dex-cool contain special ingredients that makes it better than non dex-cool?

 

Lastly, how many people have flushed their dex-cool and use conventional green antifreeze?