It's a **** shoot
High oil temps seem to be like the RV wheel shimmy. Some folks have a problem, some folks don?t.
I would have loved for my Van?s cooler to work but it didn?t so I had to pony up the bucks a second time for the SW cooler. Do you know that your plane is going to run cool? Why take the chance? It is MUCH easier to deal with low oil temp. Personally though, I would go with the Positech unit and save a few bucks over the SW and still end up with a better cooler.
There was also a question about quality of the SW unit vs the Vans unit (not to be confused with performance). The SW cooler is better made, hands down. Good luck.