So I thought I would update this thread my some more thoughts after playing with the monogut a bit more.
The tension seems to have dropped a little, to the point where I'm not really getting any bite on the ball. The string bed is also a little unpredictable and balls are sailing long that used to dip well in. I don't want to, but I'm considering using the words "trampoline like".
I think I will use the remaining set trying out a couple of hybrids with RIP Control which is my go to string now.
(sorry eelhc, I can't really help you there. Hopefully Ramon will chime in)
I got that impression too with my first set of full bed ZX. For some reason the ZX/Hexy hybrid that I was trying out at the same time gave me better results, and I thought it played as well after 10 hours as it did in the first hour. ZX/DNA was a great setup, but at 52 lbs constant pull on my PK Ki 5x, it got trampoline like after 5-6 hours, but for some reason I still felt like I had good control. Upping the tension to 54-56 solved that.
Since then I think ZX has "grown" on me. I like a full bed ZX now. In fact, my favorite was the full bed of ZX Pro until it broke after just 1 set. It might also be because I'm more conscious now of the tension loss that happens if you don't give it a good "stretch" when you string it. Even on the mains, 30 seconds is about the minimum time I'll give my drop weight machine to pull each string.
Too bad full bed ZX doesn't last long enough on my Tour 98 ESP, but ZX/Marathon outlasts anything else I've tried.