Was in the same boat last fall.
You can probably find my thread about it where it was carefully explained that I was 87 types of retarded for not getting g a chebby.
We went with the armada, for the following reasons:
1) my brother has had several suburbans/yukons, all have been trouble
2) my brother in law has a brand new (maybe 3k miles on it now) Yukon Denali XL, which has had major problems including a full tranny replacement
3) I have an 08 Titan with 160k on it. It's been great, despite a lot of abUse. It's off road daily, and frequently hauls heavy loads. Outside of maintenance items, my only problem has been damage to the electrical system on the underside due to offroading.
4) We compared a used Sequoia SR5 to a 2011 Armada Platinum (all that was available within a few hundred miles). The SR5 interior felt very cheesy compared to the Armada. Not apples to apples, but the Toyota interior felt very budgety for the amount we were shelling out.
5) This was the wife's car, and she was going from an audi s4 to a truck (kids will do that to your vehicle choices). She felt much more comfortable driving the armada. Ymmv
Either way, good choices. They're very reliable, non UAW, and you don't have to spend extra money on gold chains and drivetrains.
BTW, if you're tall, double check the Toyota. I'm 6'4" and have trouble getting into both the Tundra and Sequoia without hitting my noggin.
ETA: 6) wife and I both felt the newer sequoia looks too minivan ish compared to the earlier brawnier version