This car handles well, is fun to drive, and I feel it is safe to drive with the family aboard. But after three, yes THREE radiator replacements, 2 head gaskets and several costly sensor replacements, I'm ready to be rid of this car. It has a computer "sensor" for seemingly everything, and I've had to replace them all more than once, and of course, these sensors are never in easy-to-reach places in the engine compartment, so every time, I've been totally reamed in the wallet. I just had the catalytic converter replaced as well, and like the other repairs for this car, it was very expensive. Seriously, I owned a Toyota for 10 years, and spent less than 1/4 the cost of repairs to it.
AWD is nice, and I will miss it. The seat warmers, side mirror defrost, and fold-down rear seats are nice as well.
For crying out loud, make the sensors accessible and affordable.
Your problem is more the mechanic than the car.
He did not know how to diagnose head gasket failure and put in radiators instead.
A bad head gasket, if left for a while, will take out the oxygen sensors and catalytic converters.
The coolant is caustic to these.