I believe you. On Sunday nights, the first sober night after a few nights of binge drinking, I'm usually unable to sleep. Instead of sleeping, I get stuck at hypnagogia, and I stay there until morning. It's hard to say if I fall asleep with my waking mind still on or if I stay awake with my dreaming mind turned on. Rest-wise, it's not a great way to spend a night, but it's absolutely worth it. I'd love to be able to do it at will.
I totally understand the split consciousness aspect of it, but because I'm in bed, I can devote my full attention to what my dream half is thinking and imagining. It ranges between thoughts and somewhat-vivid dreamlike experiences (and that's actually a continuous spectrum). It's always nonsense, but it's so original and astoundingly in-depth. There's also the novelty of having conscious thoughts that don't come from "me". It's really quite an experience to be thinking "How the fuck am I coming up with this stuff?" while the other thought-voice continues concurrently! Like having two cores and being the sane one.