help understanding runes

im trying to find the best rune page to run on right now i only need help with the secondary page...

ive been going inspiration for the obvious +5% cdr and 45% cdr, i find ziggs really useful with his ult up alot more, i also get statis because ill be building hourglass at some point anyways if it goes late, and its a free outplay...

but i am wondering, would it be worth it to switch out for precision, for prescence of mind, example early/mid game teamfights send me oom fairly quickly, but my question is would 10% ultimate reduced cooldown be more or less then +5% cdr?

i would also be going for coupe de grace, obviously to snipe better with the ult levels 6-9 when it could use abit more damage....

another option im looking at is the resolve tree, but mostly just to abuse the rune demolish with ziggs passive + w to push turrets early and support a very aggressive play style of winning the bronze match before the bronze apes throw it, so any of you bronze/silver apes understand what page would be better overall? i know everything is situational but mostly id like to know whats better for a lower ult cooldown, 5% cdr or 10% reduced ult cooldown, i need to be making plays around the map to win so..