My guess would be simply Economics, Greg; It costs relatively only a few cents each to manufacture .50¢ tokens in large quantity vs. stockpiling thousands of dollars worth of U.S.fifty cent coins in each slot machine.... and tens of thousands of dollars worth of U.S. fifty cent coins stored in the cages coin banks. In addition, the casinos have to order bags of replacement half dollars from a federal reserve bank and pay additonal delivery charges for armored car services.

My question would be, "Why Don't MORE Casinos Use .50¢ Tokens?"

BTW: There are currently four Atlantic City casinos that have switched over to .50¢ slot tokens.