They are all hybrid powertrain starting in 2021, and this provides impressive economy for the size of the vehicle. We have two older ones with the 3.5 V6, a '10 and a '17 (and I bought the Camry due to the luck we had with the '10).
Our '17 has been rock solid, and is currently around 130k. No repairs have been needed - just oil changes, a couple sets of tires (the Siennas do go through them fairly quickly), I believe one set of brakes, and air filters.
The '10 is sitting in the 245k range. It runs like a top. It got a new radio in warranty (stuck CD changer, I think), and had a repair to the VVT system around 100k that became evident due to a check engine light (I think that cost around $1000, but that included replacement of plugs at the dealer - not sure on the actual repair cost). Otherwise, outside of batteries/filters and other misc maintenance, it has had an a/c recharge once, a few miscellaneous suspension parts, and one interior door handle. It currently does have a check engine light that started recently due to an O2 sensor code (it's the most difficult one to replace due to location, so I haven't tackled that yet), but I'm ok with that given the mileage. Factory fill/"lifetime" ATF is still in service, and it still shifts like it always has.
The '17 is a big upgrade in terms of features, interior quality and comfort - despite both being LE models, this one adds auto lights, touchscreen radio, auto 3-zone a/c, power doors, alloy wheels, Homelink/auto-dimming mirrors, and some other niceties. That said, I do prefer the power delivery of the '10 - the '10 has the 2GR-FE and a 5-speed, whereas the '17 has the 2GR-FKS and an 8-speed. The '10 feels much lighter on its feet and quicker, but the '17 still has plenty of power (especially when turning on the "ECT Power" setting - essentially turning off eco mode) which wakes the van up dramatically.
Neither of them have ever used any oil, and MPG is pretty decent for what they are - in the neighborhood of 19-24 on the '10 and several MPG better on the '17. I think they are probably around the best family haulers out there for your dollar. The thing that impresses me most is how well (slowly) they have aged - they seem, to me, to be a relatively better car at over 100k than they do when new.
