Hinduism is a nostalgic throw-back to the highly localized deities of primitive polytheism. I find it troubling only in the sense that it is archaic and a little silly.
The great eastern religions from Taoism to Buddhism all suffer from the same irrational metaphysical foundation which is exactly why they are so popular among leftist: they are ideologically related. No rational man could possibly take them seriously, for even a moment.
Islam has a special place in my heart though. I truly despise this religion and the only time you will ever see me in the Dawkinsesque anti-religious mode, that atheist are notorious for, is when discussing Islam and occasionally Scientology. Why is that you ask? Because Islam is truly unique, and not in a good way.
One of the hallmarks of a healthy religion is a rationally coherent and relatively consistent moral code. They should essentially engage your intellect even though they will often make absolute decrees which occasionally defy reason and they all require a leap of faith. Unhealthy religions usually resemble cults and the hallmark of a cult is that they are highly, highly prescriptive or ritualistic and usually lack any conceptually coherent moral code.
Islam is deeply prescriptive faith, more so than any other major faith other than Judaism or middle-ages Catholicism. The key difference is that Jewish prescription is often rationally derived (such as the kosher diet which prevents easily communicable diseases from pigs) or philosophically consistent with the faith and Catholicism has matured after centuries of scholarly monasticism. Islam has no such safeguards or maturity, it's prescription is as nonsensical as it is ubiquitous.
A similar feature to tyrannical governments, cults, and brainwashing techniques is the notion of arbitrary prescription and absolute submission in order to find value or fulfillment or meaning. All things come from the source, whether it's the state, the leader, the faith, or whatever and all you need to do is submit to it's arbitrary demands. Islam fits this model to a tee.
Some of it's other charming characteristics include:
an innate and baseless elitism - they are supposed to be the greatest people in the world simply because they are muslims.
Complete integration between the faith and every other element of their civilization. It's not just math, it's Islamic Math! They are simply deeply uncomfortable with any notion of separation or secularism - see Turkey for ample evidence of their best effort yet.
A sense of historical and holy obligation to make their faith the one and only faith.
Islam also, in part because of it's innate sense of superiority, is in a constant state of psychological turmoil which manifests itself in a tendency towards familiar violent outbursts, cultural nostalgia, hyper-sensitivity (see: Jewel of Medina), and bitter resentment towards other cultures.
While Islam's list or prescriptive demands is long, inconsistent, and comically surreal to be sure, when combined with its penchant for violence (not too much greater than in Christianity but far more dangerous considering it's cult-like and tyrannical nature), natural receptiveness to socialism, megalomania, and demented arrogance and you'll get a rough idea as to why I find this "great faith" so troubling.
P.S. If you find this offensive and are not a muslim then please don't bother me. Just research some of my claims - I didn't make them up, and make an assessment on your own as to whether or not you think I am taking things out of context or reacting irrationally to things. If I am wrong then I will gladly reconsider my position.
However, if you are a muslim and find this offensive then please don't kill me. I don't want to die but I would rather die than kow-tow to your pathological rage.