I think it will only matter if you plan on running your car multiple times at WOT or running it hard in general. If the oil gets too hot along with the turbo, it basically evaporates and creates a residue called coke (the process is called "coking"). Coke is basically a carbon deposit <--- dare we say the word. It's bad for the turbo and worse if it gets back into the oil pan and into the engine.
Anyway, if the oil is cooled, it cools the turbo. If the turbo is cool, oil won't evaporate, and won't cause damage. I think an oil cooler is pretty dependent based on setup and use.
But now since I typed all of that an saw that your question is will it help our cars on an NA level... I guess the same still applies. Anything that produces a lot of heat could benefit from an oil cooler. Like the transmission. It won't really add anything performance-wise, but it would preverve the life of whatever you were trying to apply it to (transmission being the common thing).
Hope that helps.
