My truck went had zero issues with the factory fill, was clean when I had it out at 185k for a radiator replacement.. (it was changed under warranty repair at 95k), I was going to change it at 200k, but changed trucks instead..
I was going to put in the Zerex G05, bought 3 gal, still sitting on the shelf in the shop but I did not like it was not dyed.. I probably would've just gone with the MOPAR stuff in retrospect but they are both good as far as I have read, but like was said make sure you flush and clean it out prior to refilling, and use DI water.