Re: Islamic History - Hagarism, discrepancies
Only ever read cirtiques of it.
As for Crone, she seems to be revising a bit:
http://www.opendemocracy.net/faith-europe_islam/mohammed_3866.jsp
All of a sudden, Islamic sources are acceptable…and their concerns seem to have shifted from the origins of Islam (or accusations of it’s fabrication over time) to understanding the historical context in which the religion rose.
I suppose the original hypothesis was a bit too much even for the author…