I have had this car for 4 years and haven't had a single problem with it! I bought it brand new when got tired of investing too much money into a 93 Ford Explorer that was going downhill. Toyota's MPG ratings are right on. I never get less than 25mpg around town and on the freeway I get 32mpg. This car is great for traveling and road trips. The cargo space is wonderful too. I play music and needed to fit my 2 bass cabs, amp and guitars into the car and they fit just fine. My buddy bought a Matrix cause he needed a new car and liked the roomy-ness (he is 6'4", 250lbs+). He fits his whole drum set and monster keyboard in his!
Love the amount of space inside the cabin. When the back seats are folded down you can fit nearly anything back there. Also, the driver seat adjustable height feature is amazing. It handles uphill driving just fine for only having about 135hp. Never even gets close to overheating.
I don't think you could improve this '06 model much more design-wise. I can't believe they made these cars smaller in the '08 models. I personally think that is a backwards move for Toyota. 03-07's all the way for me!