Will confirm the above, tuned EJ257, tracked on occasion, driven like it's stolen, and I almost never have to top up oil between services (Mobil 1 fully synthetic).
Whilst Subarus can exhibit a higher oil consumption than some other makes and dependent on driving style anything above the occasional top up is a sign of an underlying issue.
1L per 1000 Kms being "normal" is simply rubbish.
There is a known issue with the FB engines though ...
http://oppositelock.jalopnik.com/sub...ion-1600566355