Yes, if you're in a Protoss vs Protoss situation, it's quite obvious that whoever is faster and more skilled will win. However, there are some tactics that a Protoss player is only able to pull against another Protoss player.

- If you suspect that an Arbiter is attacking you and you don't have any observers available, then use a Templer to cast Psionic Storm on the region you suspect the cloaked units to be present.

- Psionic Storm can also be casted on an enemy Carrier's Interceptors since they have a tendency to bunch together in a spot when shot out by the Carrier itself.