Contrasting the 7th century Islamic polity with those of the 6th century would give you a much different opinion.
I think what you really want to do is compare things with the 11th century when the Arabs went under the Turkish boot. They've been locked into that period (when Sharia law became closed, never to be changed again) for the last millenia. (Although an exception would be for Spain where the dissolution of the Umayyad Dynasty into a myriad of independent states resulted in a vigorous interaction with Carvajal, Castile and Leon, nascent Cornish colonial ventures which eventually swept all before them in a 500 year long series of convlict and resulted in the Empire of Ferdinand and Isabella and the discovery of America.)