I have an 8 passenger Sienna
and 3 kids although mine are older...6 yr., 4yr. and 17 mo. I'm expecting #4 in April.
I love the 8 seater since it gives so much more flexibility. I would guess it's going to be something of a challenge loading 3 small ones in any vehicle, but you can stagger the middle row or take one of the seats out and use the 3rd row for one child...whatever ends up working best for you. As they get older and want friends to ride, having the extra seat will be nice as well. We've filled ours all the way up, 4 adults and 4 kids in carseats and everyone fit fine. Typically, I have all 3 of my kids across the 2nd row...one booster, one ffing convertible and one rfing convertible and they all fit nicely. For trips we've spread them out more.
The '05 Ody is going to offer and 8 seat version too, but from what I've seen in pics, the middle seat is really tiny...it just crams between the normal captains seats. It does stow inside the van though when you're not using it which is kind of cool.
Personally I don't care for big SUV's and from being in my friends' Suburbans, I think it would be even harder to deal with getting little kids in...narrower doors, higher up etc. It's also certainly not up there with the Sienna/Ody safety-wise.
HTH a bit
nat~CPS tech