I have one and love it. My 3 and 5 year old play it all the time. We have a lot of parties and the adults play it as a drinking game. Doesn't seem to get old because of the 4 player action and interaction of people.
I have 14 Pins and I am in the process of buying more arcades now. Pins are great but they aren't for everyone and I like the diversification of having other things for people to do.
Maybe not your thing, but I just picked up a DDR and my wife loves that thing more than anything we have in the house and we have some pretty solid games.