Excellent show! I have been to it about 4 times now and I always enjoy it. In regards to the free tickets, you have to really consider this. There are less than 200 seats in the balcony, and thousands of tourists with a coupon that can be found in any vegas magazine. Free doesn't last forever and they certainly cannot accomodate thousands of people in a balcony made for close to 200. Cut them some slack, at least you get the discounted tickets.
With that said, it is still worth the upgrade price and I feel it is worth full price. It is an entertaining show, great for the family and for the wallet. So many people look for a family friendly show for cheap and it is near impossible to find. Most shows start off at about 60 dollars, 10 or 15 dollars, are you kidding me? You will never get that price anywhere. Sure the balcony is free, but hardly the best seats in the house.
I recommend skipping one of the big shows that you will pay over a hundred dollars with with no child prices only to turn and see your child fast asleep, and get this show. It will keep the little buggers entertained and it won't take all of your money.