One good thing about Acupressure is that it can sharply boost Accuracy, which is great for moves like Stone Edge or Hypnosis. But that only has a 1/6 chance of happening.
The problem with it being random is that there are only 1 or 2 stats that you will want to boost at that time. If you are a special attacker, then an attack boost is useless. If you are facing a physical attacker then a special defense boost is useless.
From my experience, Acupressure is not reliable enough to warrant its use. Stick to moves like Swords Dance or Nasty Plot to boost your stats.