I find PvZ by far the hardest match up (~1300 diamond). If you open 2/3 gate robo you will really struggle against a decent zerg IMO. Muta/ling really hard counters this build as soon as you expand. As soon as the zerg gets a decent amount of mutas you are ****ed. You need to get some reasonably early pressure out to stop them going macro crazy. People used to go 2 gate but this isn't as effective any more.
I prefer going 1 gate + early starport or start by walling them in with 2 pylons + a cannon (and a zealot by the pylons if you like) into fast expand. With the early starport, get 4 pheonixes out (1 more if it's going well) and use them to pick off queens/overlords (don't waste energy on drones too early imo). If they are going for a spire keep pumping pheonixes, if they go hydras (or if you just don't see a spire) get a robo bay out asap and start getting collosi and prepare for a mid game push. You can't let them scout this build with an early overlord. Get 2 stalkers out asap and spread pylons so you can deny it.
The key to beating zerg is harassment. You need to stop them pumping drones or they will always beat you. Terran have it a bit easier with drops + banshe play imo.
That or just 4 gate them