Pat,
I have lurked long enough to know I shouldn't take the bait but here goes.
Yes those advocating for the markers have seen them in use and favor them. Read through the responses.
No, they are not designed for the whole family to play from. They are designed so the family can play together, without mom or dad worring about pace of place and so kids enjoy themselves and keep mom and dad coming back. As I responded earlier, in my family, I tee from my tees my son tees from level two and my daughter tees from level one. Read through the previous responses and you will see no suggested parentents play from 1500 yards.
No I don't need the family markers to fuel my interest. I am doing just fine without them, but do the make it more enjoyable to take my kids out and getting to the stage where they can play regular tees faster, absolutely. What all of the comment missed, is many kids like formality. They like having a marker, a scorecard, and yes they like keeping score. If you have ever coached tball, no matter how many times you call it a tie, the players/kids will tell you the score.
I'll give you lost word, but just because montclair has had a successfully jr program for years, doesn't mean others should not try new things when clubs are struggling for membership. Over 800 courses have adopted the plates. Could be a fad, but worth a try at little cost.