Hi - I've been a long time lurker here researching car seats for my 2.5 y/o "DS" (am I using these acronyms right?) and my infant DS. I'm also a huge car guy.
The Odyssey and Sienna are great choices. However, you may want to consider 2011 and newer Chrysler Town & Countries and Dodge Grand Caravans. Chrysler (which owns Dodge) heavily revised these vans for the 2011 model year and replaced the interior, engines, and revised suspension tuning. The current engine - called the "Pentastar" - is thoroughly modern, powerful, V6. Chrysler literally bet their company developing the Pentastar engine as they put it in literally every vehicle they make, from Jeep Grand Cherokees to Dodge Stratus(es) and everything in between.
Current reliability information has been very good for the 2011 and newer Chrysler vans.
As others have pointed out, it is well known that Honda vans like to eat their transmissions for lunch. Also with the Honda, you will be looking at a $1000-1400 timing belt replacement if it has not been done. If the timing belt snaps on the road, you'll be stuck. All timing belts wear out and all timing belts will eventually break, so if it hasn't been done, its worth doing (or if it has not been changed, use it as negotiating leverage).
Due to the fact that older Chryslers had some reliability issues, used prices on the vans are extremely attractive. You could take advantage of the market disparity discounting a very competitive van and get a newer, lower mile vehicle for the same as an older, high mileage import. For example, this loaded Caravan -
http://www.carmax.com/enus/view-car...+398+9&Q=feeaac26-4b56-4894-8354-67c101177f6f
You won't wrong choosing among the Honda, Toyota (or my favorite, the Caravan). If you do get a high mileage van regardless of make, you should have the transmission fluid flushed at a reputable shop unless you have documented evidence it has been done. We were in your spot not too long ago and after driving the 2011+ newer Dodges - they weren't even on our list - found it better fit our needs more than the other vans. The extra savings didn't hurt either.