So, I'm trying this for the first time tonight. Observational notes:
1) Raw leaf: too strong for me to eat in a salad or whatnot. Maybe cooked in some dishes with other strong flavours.
2) Tea taste (I used 5 large P. edulis leaves in an oversized coffee mug of near-boiling water): the first taste I got was just "leaf". Nothing else. Kind of unappealing, but not distasteful... just uninteresting. However, the more I've been drinking it the more I've been picking up this subtle mint flavour that wasn't there in the beginning.
3) Either this was some crazy timing, or maybe I'm having a very strong psychosomatic effect..... OR, this stuff does exactly what it says on the tin. I was only a quarter of the way into the mug when I noticed that I felt sleepy. And not "normal sleepy"; but like something was actively dragging my awakeness level down. Yet not of the type of effect to cause an imminent "fall asleep at my computer" effect. I'll just put it this way, I don't think I'll have any trouble falling asleep tonight.
I also have this sort of heavy and/or tingly effect around my head.... maybe a very tiny bit of that feeling you get when you've had skin numbed for a medical procedure. But again, not a strong feeling like that.
I definitely have to try this again to see if it's a coincidence or if this is a consistently reproduceble effect. But so far, I have to say that I'm believing these reports.