My impression is that most Muslims are what any reasonable non-Muslim would call radical Islamists, and while they may 'tut' at the beheadings and so on as counterproductive, they are ambiguous about it, and don't condemn it.  In other ways almost all Muslims are "fundamentalist" (in the sense that they do believe and don't rationalize or claim metaphor) whereas most Christians are not.

In my mind this makes Islam dangerous, and, while individual Muslims may be good neighbors and all that, the community will constantly produce very dangerous young men.  It's inherent in the meme.

Another thing is that while Muslims practice charity and love, it is reserved for only other Muslims, and generally even only for the same sect.  Some Christians are that way too.  It always gets me when religions broadcast their charities and don't mention this.