I don't know about everyone else, but all I have seen Dex-cool do is screw up stuff.
First: I have a friend that has a 96 Impala SS. In 96 he had to take it to the dealer to have the radiator replaced because it was half clogged. At the time it had only 5000 miles. In 97 he had to have it worked on again(at the dealer) and have the heator core replaced. It too was clogged. In 98 the same thing again. After that time he drained the system and flushed it out. Then replaced it with regular antifreeze. No more problems till this day( has 110000 on it now).
Second: I bought a 98 GTP. It had Dex-Cool in it. I could see some "goop" floating in it so I flushed the system and replaced it with some fresh Dex-cool. It wasn't long before I started having some cooling problems. I had about 6000 on the fresh Dex-cool when summer hit and then the car started over heating(not to bad, but bad enough). I flushed the system with fresh water then a bottle of radiator flush from AutoZone. You wouldn't believe the sh*t that came out of the cooling system. Looked like goopy Dex-cool. Now I run regular antifreeze and am trouble free and cool running.
Third: I have worked on many newer cars that have Dex-cool and have this goop floating in the radiator, even with low miles.
So, I would say, dump it, flush it and replace it with something else.
Just my .02!