I, too, was intrigued. After reading all the reviews on Amazon, I thought I'd give it a whirl. Fortunately, my library system had 3 titles I could try out. I was completely hooked! It's different than Hatha & Ashtanga--I wouldn't say it replaces it, only compliments it. For me, Kundalini is so helpful because it works the spine and neck as well as the organs and glands--and you breathe a lot! It's pretty bizarre to look at sometimes, but it feels soooooo good when you're through. It is wonderful to de-stress and get things back into balance.
Coincidentially, it was about this time last year when I first heard of it. Fast forward to this year, and I have all the titles except one. I can't go a day without doing at least a little. I wish I'd known about it years ago--I'm much nicer when I practice it.
I'm sure it's not for everyone. But you really have to try it (not just view it, because you look ridiculous doing it) to see if it is of benefit to you. Try your library system or Netflix so you won't be out any money if you don't like it.
Hope this helps,
Elsie
P.S. I'm not much into the "mystic" side of yoga, as I have my own religion. But I find that I can translate yogic principles into the terminology of my faith. Ravi is a good instructor, but his sayings can be a bit cheesy for my taste. Fortunately, it's easy enough for me to ignore him when I want to.