It saddens me to see that my Indian friends have so many problems with the American Express card. Overall, I have found it to be the best card ever. Although it was difficult to obtain, and the questions were more intense than the other cards, once I got it it has been a lifesaver on several occasions.
When I need to travel in a hurry, there is no concern about credit limits or waiting times. The customer service has been remarkable - friendly, polite and extremely helpful. They also offer online service to avoid waiting lines on the telephone.
It is true that not all merchants accept this card. It is a bit more expensive to them. For them, I carry a different card or pay cash. Still, my preference is definitely for American Express whenever possible.