Hi, Sendaiben.

I'm a Family Plan member and absolutely love it. We rack up the miles through credit cards, use 'em to get coupons and/or upgrades, and all four of us (kids are 2 and 3 y.o.) get to use the miles. The only thing it doesn't 'pool' together is fly on points, of course. The kids' mileage from travel can be used by me or my wife if we need to travel alone, too. It's especially nice to upgrade when traveling alone with a child.

Hope that helps.

Kento