I'm a long time lurker here. I have a '97 OB auto with 100K miles and a '01 Forester L auto with 35K miles. I just had the heater core replaced on the OB. The mechanic said it was related to the extended life coolant I was using. He also said he had not seen any head gasket problems. Not many Subarus here in Huntsville, AL. He is the only Sube mechanic at the dealer. No other problems with either car at this point.
Dave