I saw one very unhappy young lady at the dealer today with a new Impreza using a quart in 1200 miles. I don't recall any threads on the 2.5 engine using oil. Mines doesn't use any hardly any in 4500 miles.
I just went 7500 miles between my last oil change, I'm using full synthetic since 1K miles new. Have 29K now and the car has not burned an ounce of oil yet. My 2011 Ford F-150 V8 goes through 1/2 qt every 1000-1500 miles, Ford says thats normal and ok.
I have 2100 miles on my '13 WRX 2.5 turbo and it has not burned an ounce of oil since new. I'm guessing the new Impreza lady didn't break in her new car correctly. As an example, people ike my neighbor who start their cold car thats been sitting all night, she gets right in as soon as the engine cranks over shes already reversing before the RPM's even drop, then it's almost full throttle up the street with bluish black smoke pouring out of the tailpipe on a 2-3 year old 4 Cyl Camry. I'm thinking this lady with the Impreza has a similar driving style.