One of the few I haven’t used but Ben greenfield had talked about it a lot in various podcasts,
from memory it only affects the delta phase of sleep and there is some debate as to whether it actually improves sleep at all (depending on how it’s measured).
you also build up a tolerance pretty quickly to that one so use sparingly.
I looked at it a while back as I’m desperate to improve my sleep (on blast gear I average 6 hours despite being in bed for 8+ and not consciously awake that much, on cruise doses I average 6.5-7 hrs but again in bed for 8+). This is according to my oura ring.
restfulness appears to be my biggest issue but I recall thinking that dsip wasn’t a solution for me.