Here's the short story; I'm playing in a 3.5 singles league and since using ZX Red 16 I'm hitting the ball consistently deeper and with more spin. As I get used to the string's characteristics/power level, I'm gaining better control from match to match. Comfort is outstanding. After not playing all winter long, I started the Spring season full out and as a result felt a lot of discomfort in my wrist and elbow. Since switching to ZX, not only have I been able to play pain-free, it's almost been therapeutic
I'm reading a lot about people searching for the right tension or hybrid for this string. As with most tennis equipment products, as a community, we are probably over-analyzing things. If one of the reasons you use poly is for its power deadening quality, then this probably isn't the string for you no matter the tension or hybrid, but if you need or enjoy using a mid to high-power string, then there are very few (no) choices that offer the combination of qualities that ZX does.
Remember this, you are lucky to have lived during the golden age of beer (except Guinness, Heineken and Sam Adams).