I’m no expert at all, but I have known some of them, prayed with some of them, and have been to Mass twice in a charismatic-inclined parish.
I’ll admit the speaking in tongues is a bit off-putting to me, though at the Masses when they started to sing, I didn’t even realize some, perhaps most, were singing in tongues. It was pretty, really.
Some of the people are just the kindest people you would ever meet, and seem sincere to me, and the laying on of hands they sometimes do just seems gentle and kind.
But I’m not a charismatic, and am unlikely to become one. I don’t know how people come to it.