I can't not attest to all the chevy/GM models but I can say the many that we've repaired are the tahoe's, trailblazers, suburban's & denali's but I would advise anyone with any chevy's in those years to be aware of this issue, many are loosing their brakes.
That said, Charlie your Sienna is a vehicle you will be very happy with for many years to come and make sure you do 30K 60K & 90K services and it will last many moons!!! Personally, I'm a Honda gal, I have the Pilot but would love the Element as a dog car. It's on my list!!!
Oh, and the Ford's, stay away from the 6L or the 6.4L motors, major issues. (once again, this is all just my experience & opinion)