They provide a beautiful experience, which is insightful exclusively to the degree that it allows you to realize the arbitrary nature of your sober presence of mind, which in turn provides a certain experiential awareness that many of your preconceived notions about certain things are unfounded. It can also illicit a pleasant feeling of interconnection between things, which isn't in fact "hallucinatory" in nature, although it is accompanied by hallucinatory visuals in the form of something like sheets of visible geometry.

It can do nothing beyond that, and anyone who gets wrapped up in thinking of them as a definitive "spiritual tool" is on a long road of misguided naivety to disappointment. They do not provide answers to anything. Only more questions. For resolving questions, one still must rely on rationality.

They are certainly worth doing 2-3 times, in my humble and possibly heretical view. I would heavily advice stopping at that point though. They will quickly lose their "magic" over time, and it's far too easy to become needlessly attached to them as a superficial surrogate for proper religious discernment.