Yeah, my family came to visit me at WDW for Christmas last year. It was one of the best times we ever had.

CPs like to hook each other up. By the end of your program, you'll have met A LOT of CMs from all over the property. If your family comes, you're likely to get them some perks (aside from the deep, deep discounts). This comes from your friends and even casual acquaintances ("Hey, you're my neighbor!" or "Hey, I think you know my friend X")

In my case, it was "special" fast passes to many rides, VIP room at Cali Grill, special seating at Fantasmic, etc. Never asked for anything, but CPs are happy to help each other out. It was a really wonderful time.

Needless to say, my family was very impressed!