Well, there's nothing special about AMEX as compared to Visa and Mastercard in general. As a matter in fact, Visa and MC is more widely accepted as compared to AMEX. The merchants don't care what card you have as long as the transaction can go thru.

Having said the above, AMEX Gold Credit Card does give you 5X reward points for Petrol, Groceries and Utilities which works out to be about 2.5% cash back. Go to AMEX site and check it out. If you dont spend much on petrol and groceries then you won't miss much.

Also, since November 2009, AMEX is giving 15% cash back at malls in Klang Valley which is something other cards can't beat but the cash back have a maximum payout of RM4 million.