Good question. I'd like to know if going with AMEX is still as limiting as it used to be. I recall many restaurants not accepting it and only VISA and Mastercard.
AMEX has much broader acceptance than it used to, given that more retailers are going to CC services that accept all. In fact, of those places that accept only 3 cards, Discover was left out more than AMEX.
One of the few that don't accept AMEX but do Discover is the San Francisco Giants (for tickets).
One of the few that don't accept AMEX but do Discover is the San Francisco Giants (for tickets).