Just something I picked up in experience. If you're changing your break fluid this is my advice. If you use the brakes enough to warrant the use of Dot5 fluid OR don't mind changing your fluid more often then by all means use it. But if you're a person that is just daily driving with some spirited driving and/or don't care to change your brake fluid once a year, stick to what Subaru recommends.
Dot5 like ATE Super Blue is more hygroscopic than your average brake fluid. Meaning, it will get contaminated faster. I realize brake fluid is hygroscopic to begin with. People may have different experiences as I have. I changed both the WRX and the Outback (left over fluid) at the same time. The WRX is still fine and the Outback is in desperate need of a fluid change.
"We live for a good time, not a long time."
RIP Colin McRae