Ah ok. Would be interesting to know exactly how much effect the flat four has on the CG.
I can't find the article I read now
but the lower CG of the new RAV is only slightly lower than the Forester but has to make do with quite a bit less clearance. As for how well a boxer works in keeping CG low, ask an FR-S driver.
There are other advantages to the boxer. Longitudinal mounting means the trans is behind the firewall and the front half-shafts can be made identical lengths. Subaru goes on at length about "symmetrical AWD" for a reason. With the system having equal length half shafts front and rear, it minimizes torque steer and when the AWD system moves power side to side it works very nicely.
Downsides to the boxer? The engine has two heads, two timing belts, etc. Things like plugs can be tough to get to. On most Scoob models, the areas between the front of the engine and the rad is super tight.
Not specific to boxers, but to Subaru is the sound. I love all the noises the 911s boxer makes, and the old air-cooled cars can be very raw and amazing to hear. Subaru? Not so much.