I prefer Toyota Sienna

I tried both, and got the Sienna. It is very easy and light on the steering, good for ladies. It is quieter on highway. The real gas mileage (70& highway 30% local) is 22, while Honda Odyssey is only 19 (based on my friends).
Also Sienna is not that boxy, turning radius is really small(like a sedan). There are 3 Siennas in the small street I live, both of my neighbors (white Americans) also got it.

By the way, do try them on highway to test the road noise...