In message , at
15:37:41 on Wed, 6 Nov 2013, John Rumm
remarked:
Amex charge more AFAIK.

I use a credit card in the same way you use a charge card - DD set up to
pay the lot off monthly. What extra does the charge card give you?

Amex used to claim the "no fixed spending limit" as one of their USPs.

Later changed to "no preset spending limit".

However, like an "indefinite" US Visa (which means "we don't yet know
when we'll cancel it", rather than "for ever") all that "no fixed limit"
means is "we'll alter the limit up and down depending on your spending
pattern".
--
Roland Perry