Old Subarus had low-range gearing and a proper part-time 4WD system, making them way better off-road than anyone ever gave them credit for. Modern-day Subarus have multiple different AWD systems of varying degrees of off-road competence, but they're all lacking the low gearing that allows the driver to ease the vehicle through tougher sections of trails.
I much prefer manual transmissions, but everything I've read says the automatic transmissions come with the superior AWD systems. So, which late-model Subaru has the best AWD system? Which distributes torque the best? Obviously, the STI's is the most advanced but that car isn't meant for high-clearance trails; I'm more interested in the Outback or Forester.
My frame of reference is hardcore rockcrawling 4x4's. I've always enjoyed automatic lockers and air lockers, low gearing, and a proper 100% front/rear lockup in the 4WD system. My daily driver is a 2-inch-lifted Suzuki SX4 with oversize tires and lots of skidplating. Its manual transmission gives me a deeper 1st gear than the automatic provides, but at high altitudes on steeper trails, the clutch takes a lot of abuse because of the 2-liter's meager off-idle torque. The Suzuki's AWD system works better than one would think, but its computer-controlled wet clutch (mounted ahead of the rear differential) can eventually overheat and auto-shutdown to allow it to cool after extended use in deep sand or snow where it's really fighting hard to distribute maximum torque from the spinning front tires to the gripping rear tires. The ESP system does a surprisingly good job of simulating a pair of limited-slip diffs by applying brakes to the spinning tires, but with extended use it'll build up enough heat that it starts boiling the brake fluid.
I guess I work my cars a bit harder than the manufacturers intended.
I'm not criticizing the SX4's AWD system, I just like to keep things simple and as effective as possible. I like low gearing (or high-stall torque converters) to allow big torque at slow speeds. I like mechanical limited-slip differentials (or even better, full differential lockers) to allow consistent, effective power transfer to the tires with traction. My SX4 goes about this the fancy-schmancy way, but it works - and my addition of the lift kit, skidplates, and aggressive A/T tires was a huge improvement.
I already have a couple of hardcore rockcrawlers for the extreme trails. What I'm wondering is which Subaru AWD system is best for high-mountain trails? Fire roads with rocks strewn about, deep washes that can get 1 or 2 tires up in the air, and steep climbs at high altitude where off-idle torque is of critical importance? Here are a couple photos of the types of roads I take my SX4 and on which I would take a Subaru: