Royal purple will void your warranty.
It has additives in it that Subaru deems as damaging, whether it actually is or not is moot. But if Subaru sees that you use royal purple in your engine, and you make a warranty claim, you will be denied and warranty will be here on out void. I would stick to either Valvoline Syn Power or equivalent store shelf oils or you can always buy the OEM Subaru oil, it's no more expensive than Valvoline or Pennzoil.
You have a brand new car, don't even chance it with going outside the realm of Subaru's guidelines until your out of warranty. You should just learn the car, drive the car and enjoy it for what it is right now.
Research it, learn it, and just soak in as much knowledge as you can, instead of just asking what everyone else runs. Most of the people who will want to keep the warranty intact will go by the guidelines of what Subaru says, everything is stated in the warranty manual, 80% of new car owners will never ever read the warranty manual, I highly suggest that you do, very important info in there.
My professional opinion being an engine builder, mechanic, and tuner is: Use a OEM Oil filter, and OEM Subaru oil, that way if something happens, your not liable for shit.
I hope this helps you make an informative decision.
And I hope your enjoying your new car.