A Subaru dealer when replacing a leaking cv boot on the right side suggested replacing the left side, too, stating it was dry and cracking. They also told me of a head gasket leak but gave no other information of use about that.
Jay at Excel Automotive checked the cv boot and even took digital pictures to show me that they were all in serviceable condition and none needed replacement at this time. He also showed me the picture of a minimal valve cover seepage of nearly no consequence and rather typical of a high mileage engine.
Excel did not charge for this inspection but they did earn my future business and recommendation to friends.