To be honest with ya mate Subaru service history wouldn't be a reason to buy a car.
There are specialists on here that would take care of the car better than subaru. If I was looking at a subaru & it had been maintained by Ciaran (RS RA) or Johnny (jomo) I'd be more than happy that the car has been looked after as well as possible.
Main dealer will most likely get you an apprentice working on your car & an overpriced stamp. Fine if the car is new & you'll be looking to trade it in again with same garage but worthless otherwise.
Just my opinion of course