I've rented my share of minivans, both for work and because I'd been saddled with one when the location is out of anything reasonable. Generally, the minivans that I get are underpowered, unmaneuverable wallowing behemoths that have trouble getting out of their own way.
Alamo/National at Logan has the great feature that if you use their self-service kiosk, you get to choose any car in the car class you've reserved. I went out to the lot and was confronted with a row of minivans, only one of which appeared to have Massachusetts plates. I picked that one, which happened to be a Sienna. It turned out to be an excellent choice.
First of all, the thing has some serious balls. We loaded seven adults into the thing. I found myself apologizing for the acceleration. Pulling away from the Mass Pike tolls the thing flew off the line when I put my foot down. And it did it with authority, smoothly and without fuss.
Moreover, I expected it would be hard to maneuver, but a couple of tight U-turns--not on the Pike--demonstrated that it's turning radius was much tighter than I would have expected. I didn't put that to the test at any real speed, but the limited maneuvering I did do made me feel fairly confident, as there wasn't a great deal of body lean when cornering, at least not compared to other minivans.
After all of that, it still got 19 mpg.
I'm not in the market for a minivan. Nonetheless Toyota has done it again and produced another example of why they're the world's most successful car manufacturer. And I'd certainly consider a Sienna in the unlikely event I were ever shopping for a minivan.