importance of certain safety ratings

We have been looking at used Siennas and Odysseys and the thing I keep coming back to is the safety ratings. Granted both are very good, the Odyssey wins out safety wise in my mind therefore I'm leaning toward it. Obviously the years change too, but for the most part the years we can afford are virtually this, for example:

2008 Odyssey:
Passenger: 5*
Driver: 5*
Side impact front: 5*
Side impact rear: 5*
Rollover: 4*
IIHS Ratings: on a scale of poor, marginal, acceptable, good
Frontal offset test: Good
Side impact test: Good
Rear crash protection/head restraint: Good

2008 Sienna:
Passenger: 5*
Driver: 4*
Side impact front: 5*
Side impact rear: 5*
Rollover: 4*
IIHS Ratings: on a scale of poor, marginal, acceptable, good
Frontal offset test: Good
Side impact test: Good
Rear crash protection/head restraint: Poor

How would you feel about the Sienna vs. the Odyssey based on this? Are these ratings where Sienna rates 4* or poor important/make that big of a difference between the two? Just wondering how others feel and trying to see if I'm making a big deal out of something that isn't! Pricewise they are about the same, but the Sienna is more comfortable to me and there are alot of extras that you have to pay more for with the Odyssey. Just feeling this out

My opinion is that the IIHS rear crash protection rating is the least important. It's a very subjective evaluation of seat back and head restraint adjustments and no actual crash test is done.

Beyond that, I've always considered 4* and "acceptable" ratings to be fine. Not quite as good as a higher rating, of course, but not a major drawback, either. I am concerned when I start to see any 3* or "marginal" ratings, especially in the frontal or side impact crash tests.

I think both the vehicles you listed are among the safest available for that model year and will protect your family very well. Other factors like seating configuration, price and options might be worth consideration too, given the relatively similar safety ratings.