Ahhh I don’t mean to brag but, they’re instant.
Like I have a standard ZP secret custom (hint: it has WANTED as the only core
), and mid loop I get nudes from girl randomly (I was just watching some anime at that point), and her telling me: “I miss tasting your c*m” 
This is also the reason I use subs as necessary, for example: I have King ZP, which is perfect for work and professionalism, and I’m keeping that one strictly for the days I have big things going on at work (events, partnership meetings, etc.), but when I’m just chilling with life (like this week and the next), I don’t run it.
Yes they complement each other way too well, but it takes conscious guidance to mix them properly, but from what I can tell, the reason they mixed so well for me is due to the nature of my job and life.
Mind’s eye is probably the most underrated sub in the entire subclub store catalog, and I’ve been trying to tell people to run it since ages, some of the people I recommended ME to loved it, like @bombayduck @Moon @Brandon (might be missing someone), but yeah, it’s an amazing addition to any stack.