I had also settled on Ecohitch as clearly being the best option due to the fact that it's the only "hidden" option that goes inside the bumper, which also means its higher up than other options and gives you more ground clearance as well. It's going to be more work and more expensive to install, but seems totally worth it.
One thing that I just noticed recently when looking at tongue weight considering putting a motorcycle carrier on the back of the car, is that Ecohitch by its design also gets a significantly higher tongue weight than any of the competition. All the other ones I have looked at only support 350 lbs. tongue weight, while Ecohitch supports 525 lbs. tongue weight. Honestly, even if I'm not going to go up to that weight, I like the confidence that the overbuilding will give me on the hitch strength. I don't know if I'll actually put a motorbike carrier on there, but I know that I will very often put my 6-bike mountain bike rack on there fully loaded, which is approaching the 350 lbs. regular limit, and it's nice to know that you are not constantly riding the edge of the rated tongue weight.
Anyway, we got a bit off on a tangent from the original topic... due to concerns that I might be waiting 3-4 years to get a Sienna from my local dealership, we ended up putting another deposit down with an Alberta dealership that does very high volume sales where the salesperson was talking about a 1-2 year wait instead... I don't know if he was just being optimistic to get my deposit or what, but I figured we should at least hedge our bets a little bit by putting a second deposit down with someone else. All the BC dealerships I talked to had waitlists indicating 3-4 year waits or weren't even taking deposits anymore.