I personally think the Sequoia is a no brainer for a family compared a 100. It's a lot more truck for less money and I doubt you see the differences in "toughness" at Safeway.
We have friends who have a place in the mountains where you need basic 4wd to get to the house in winter (relatively steep dirt road that is plowed but typically packed/icy) and they have 140K on a Limited without any significant issues. That truck has been used for a lot of mountain miles in winter as they ski.
Of course, if you don't need the extra space then its a waste, but to me the 100 is a replacement for an 80 (when your usage fits) whereas a Sequoia is a complement to an 80 that delivers a completely different functionality.
And I have been absolutely floored by said Sequoia heading up I-70, both rigs loaded up with family and ski trip gear. Of course, mileage tends to be fairly high before price really comes down...