My one thought here. My wife drives a 470 and I love the vehicle. Its so much nicer to drive than my Ram. It will be a much nicer and quieter ride than the Sequoia. The Lexus is AWD as well. Sorry, the Canuck in my will let you conver yourselves - we get 12-13L/100km on the highway and ~16L/100km in town.
My only concern is the Automatic Air Ride rear suspension. I don't know how that would work with a WDH. If you loaded down the back of the lexus, it will fill with air to relevel itself. We don't haul with ours, that's the trucks job which would do it much better anyways.
Just a thought to look into.
Personally - as a driver Lexus >>>> Sequoia, no question. Pulling a trailer, I'd likely give the edge to the Sequoia.