I experienced, during breath meditation, what seemed to be going directly to the second jhana without ever passing through the first. And then later, the first jhana during another session. It was mystical to me and then I understood the idea of clinging to the jhanas being a danger, because in the sittings afterward I know I was really thinking about the possibility of getting back to jhanas and worried about that. But I cannot say that it has helped me to practice in daily life or has brought this being closer to nibbana. Probably I am further away now, than then..
So I had this experience, but to me, practice outside of formal meditation is what has been really beneficial.. Just trying to be mindful of the body, contents of the mind, practicing right speech, or contemplating how my own near past actions make sense in the context of the chain of co-arising. The jhanas and so forth, they are attractive goals in the path, but probably to 'dwell' in them and use them..someone would already need to have mastered the simple things, engrained the basic teachings into mind and seeing the dhamma in everything from an intellectual standpont first. Nowdays, I don't even care about hitting jhana ever again. I just sit, and like Ajhan Sumedho suggested, I note the body, the mind, and 'it is like this' without any idea of gaining jhana or goal of attaining nibbana. I can imagine the truth of the idea, nibbana is something you get when you stop wanting nibanna. It makes a little sense to me now, the catch-22, that harder you want the fruits of the path, the further off the path you are going. Because there is no you to have those mystical experiences in the first place.
Ajahn Amaro has put it well in his talks, I am paraphrasing "We don't study dhamma or realize dhamma, we are not something outside of dhamma to see it from the outside, so to realize the true nature of things we need to see that there is no difference between the observer and the observed" Other teachers like Thích Nhất Hạnh put it pretty much the same way. In summary, there is nothing mystical to be found..like they said above, it's all dhamma. I remember when starting my practice, that I thought that I was practicing for nibbana or some kind of special thing..today I am just practicing because it makes sense to me to follow the path..if I get something mystical or have some fortunate rebirth okay, but I'd never expect it.
The most mystical experience for me, is probably having some severe 'losses' in life like divorce, loss of other loves..being pretty much crushed down and having my goals blown apart, being 95% in the pit. So...maybe go get divorced, or enter a war zone or something..haha. Then, it's easy to start to see the dhamma nature of things and it starts to fit together. If life is going 'well' in the wordly sense, the dhamma seems hypothetical..but when forced to let go of things..to see suffering in my clinging in real world examples, that's a little mystical when you see dhamma in real life and it makes sense. That's even more mystical than the jhanas..when you can feel, hey life is showing me what the Buddha was talking about. I sit and meditate, but just looking around in inside my own mind and actions teaches more about the dhamma than those 'jhanas' or whatever taught me. I am a little perplexed about how some of the Asian teachers who ordained as boys, are able to deliver profound teachings..perhaps they realized the dhamma through mystical experiences.. because entrance into monastic life as a boy, would pretty much shield them from experiencing much of the hardcore opportunities for dhukka and practical world experience that many years of laylife provides. The "opportunity to experience suffering." Maybe to learn about mystical experiences, it's best to talk to a life-long monastic who might have gained their understanding through that path.