Magnesium glycinate is generally well-tolerated and I at least haven't experienced any vivid dreams, out-of-body experiences, Casper attacks etc.
One thing about magnesium that I don't understand is why it's taken at night like a pharmacological sleep-aid. Shouldn't people be taking it to address a magnesium deficiency, the result of which should be a calmer state than if one were deficient? It seems like a better idea to take it in a way that doesn't interfere with the nutrient absorption from other foods first and foremost, though I suppose right before bed could satisfy that requirement.