We have on 05 Quest. I love it! Nobody really ever talks about them here. We also looked at Siennas, and I liked the Quest better, and we got one for a better price. I've heard the 04 models (the first year of the redesign) had lots of issues, so I might not get one of those. We got our 05 used in 06, and it had an extended warranty. But, we've had no issues with it other than the power hatch stopped working. You could still manually control it, just the power didn't work, and they fixed it under warranty.
It's very roomy inside, I felt it was noticeably bigger in the back seats than the Sienna we recently rented on a trip.
For seats, I don't have a ton, but I've never had trouble. We've installed an SS1 with seatbelt or LATCH in the captain's chairs easily, Evenflo Generations in the captain's chairs with LATCH easily and with seatbelt in the 3rd row, Graco Cargo with LATCH in captains chairs, and with seatbelt in 3rd row. We've also installed a True Fit RF and FF in the captains chairs with LATCH. I don't remember if we've ever tried it with the seatbelt.
The captains chairs seatbelts have rigid stalks that do point forward somewhat, so I can see them being somewhat difficult for certain seats. But, the ones we have haven't been an issue. Maybe I'll try to TF with seatbelt, but dh has the van today.
One down side is there is only LATCH in the center of the 3rd row, and there is only that one top tether. I don't know if more can be added, I've never looked into it.
Let me know if you have other questions, we really like it. It has great safety ratings too. If you're looking on informed for life, the last time I checked they didn't have all of the ratings in for the Quest, so some of the figures were just averages and it made it look a little lower than it should be.