if you look at all the bottles of coolant almost 90% of them are going to be dexcool. so long as you dont have any air in the system or any leaks then the dexcool is fine. everyone hates on it, but they dont know why they are hating on it. dont be like everyone else and just jump on bandwagons because they all have invalid opinions that you think are true.

leave the stock thermostat. it wont help you to have a colder one.