I have been an Amex card holder since 2006, first in Singapore and then in India. I also have a citibank mastercard but I primarily use Amex. In Gurgaon atleast I have hardly faced any problems in using this cards. Also with eZeclick you can now use this card from your mobile.
It’s really very easy. On the downside some small shops dont accept the card but these are places where I generally use cash anyways. My citibank card is almost inactive now. Amex should do something about the fees and also be more conscious of going into lower segments as the brand value gets diluted