We purchased our Sienna 14 months ago and have driven it 19k miles.
We still have our 2001 Sienna with 135k miles on it and the new van has improved in every way.
Didn't like the van at first because of the ride, but replaced the run flats with normal tires and it now rides and drives like a luxury vehicle.
We get about 20 mpg in town and 25 mpg on the road.
So far, we are very pleased.
Love the space, all wheel drive, the ride and the rear entertainment system
Interior materials on the dash could be better, but this is a minor detail.
Get rid of the run flats and have the vehicle come with a spare tire or a repair kit for normal tires.