Re: Honda Odyssey vs Toyota Sienna
I went through the same debate two years ago. All the reviews I read at the time said that the vans are a toss up.
I went with Honda largely because of the subjective "feel" of navigating. As mentioned by doubleG, both vans are HUGE, but the Sienna felt monstrous when behind the wheel and the Odyssey felt more manageable for moving/parking in tight areas. (base 2011 models in Canada didn't have a backup camera - neither Sienna nor Odyssey)
The second factor was $$. Perhaps it was indicative of what was selling at the time, but Honda had a large "end of year" rebate ($4k, I think? Or maybe only $2k, I forget). The Toyota dealers gave 0% off list price ... I was in shock and thought it was me, but my bro in law had the same experience as he was looking at a Tundra. Never had that experience at a dealer before ... there wasn't much to talk to the sales guy about ... lol.
Anyhoo, two years and ~22k miles later, we are pleased. My thoughts on "the good":
1) Ody looks great from the front & rear. Side view is an acquired taste.
2) Ody has great highway mileage as it shuts down 3 cyl and goes into "ECO" mode. 28 MPG or more (depending on load, conditions, terrain) is expected.
3) Interior is comfy, looks good, easy to clean. (Sienna's interior looked cheap to me ... another admittedly subjective comment.)
4) The ride is as good as it gets in a van. (The Sienna ride is not at all bad either.)
5) I've had no mechanical issues at all so far (still early days).
1) The climate controls in the base 2011 are the worst I've seen in any vehicle! I have no idea how the design made it to production.
2) The stereo in the base does not have speakers in the rear pillars. Therefore the occupants of the third row can't hear very well. Another remarkable shortcoming (lots of stuff on the forum) ... but perhaps not a concern if you are getting a higher trim package.
3) The wonderful ECO mode worries me. (I'm a tech engineer as my real job ... and I don't trust electronics and software in cars or planes ... lol) I plan to keep the van for 8-10 years and the longevity worries me a bit. Sienna gets good mileage too (for its size) and has a more "conventional" engine.
4) The Odyessy is not the greatest in snow (not a concern in LA, but I dunno where your travels take you). This sounds odd, but it's "handling" is fine once moving. But the traction and getting moving is not as good as a Caravan in my experiences. I don't know about the Sienna in snow. (and yes, we have snow tires on all our vans)
Sorry for the long post. I hope it helps in some manner. Good luck!!