I actually use both, mainly because Tamiya was not available for some time and now that I have testors, I might as well use it up. But, the Tamiya is easier to clean up and does not require much effort, plus, it is truly clear. I have had issues with the Testors in drying time and having to rub it out more than Tamiya. Wet look is just a tad thicker and that can really throw a wrench in the works when you are trying to control your amounts.
I prefer Tamiya, and as they say, you get what you pay for.