What's your application for DOT 4? DOT 4 has higher wet/dry boiling points but absorbs moisture quicker than DOT 3 and requires more frequent flushes. DOT 4 is great for track days, but if you change your brake fluid once every four or five years, stick to DOT 3 on the street.
That said, ATE Typ 200 is the best in my opinion. Yeah, Motul and other racing fluids may have higher specs, but ATE Typ 200 will fall off spec slower than any race fluid. I personally wouldn't use Motul in a street car unless I flushed it every two months and I can't afford to do that.
After speaking with a Continental-Teeves chemical engineer, I learned that ATE Typ 200 degrades slower than other brake fluids because it can hold more moisture in suspension than other fluids. According to Continental-Teeves, ATE Typ 200 is good for 24-36 months in street applications.
I used it for years flushing it every 24 months because I drive in the Rocky Mountains on roads with no guard rails and a few 1,000 ft drop offs.
After speaking with another chemist at Champion Brands, refiner/manufacturer of several types of automotive fluids, I learned a few more things and switched to NAPA DOT 4. It's a lot less expensive than ATE and a lot more available. I flush it every year. I guess my bottom line is brake fluid degrades as soon as you open the bottle and I feel better flushing lower spec fluid every year than keeping higher spec fluid in my system for longer periods.
Remember that the ingredients that make DOT 4 perform better than DOT 3 are harder on your brake system components. You must flush DOT 4 more often than DOT 3. If I didn't drive in the Rockies or do track days, I'd use DOT 3 and flush every year to maximize brake system life.
By the way, ATE Super Blue is identical to Typ 200 except for color. It's off the market in the USA because the DOT specifies the color of brake fluid and blue is not approved. It was great while it lasted because you could switch every flush and you could easily tell when all the old fluid was out. Typ 200 goes from dirty amber to green to blue. Super Blue goes from dirty blue to green to amber.
Unless you track your little Hondas or pull 20,000 lb. horse trailers over mountain roads, you're better off with DOT 3.
I think Amsoil selling brake fluid is pretty funny given the long OCI mentality of Amsoil users. There is no such thing as long life high performance brake fluid and I'll bet a lot of Amsoil brake fluid users assume long flush intervals.
