Considering the depth of your reading thus far, I'm not sure how much of value you might gain from it, but the Karen Anderson book my prof recommended as a general primer to Islam -- "Islam: A Short History" -- seems to be doing quite well on that score for me, someone with previously only a vague idea as to the religion's exact history and character. It is short as advertised (only about 180 pages if you don't count the timeline and appendices), but accessible and appears to be pretty thorough, and even accepting that she must be glossing over many details in the compressed format, has still taught me quite a bit so far. I would at least recommend it as a starting point for others lwho share my ignorance. How's the Fragmentation of Afhganistan book? Worth looking into?