I don't know anything about the others that you mention here, but from what I have heard of Scientology, I would steer clear of getting involved with such a "cult". That is my personal opinion. It doesn't hurt to learn everything you can about every one of these views. In order to have a higher understanding of the world, and to gain knowledge to put yourself into a position for being a more "spiritual" and peaceful being, it is important to look at everything, and to do so objectively without settling into any ONE belief or belief system.