Yea, I use them - when you're a lower level, or have a big disadvantage, it's a huge help. Instead of raging because the npc used sand attack 10 times in a row, I just throw on an X Accuracy :p that and dire hit are the most helpful, in my opinion.
They're also great when using an offense/defense weak pokemon that isn't overleveled somewhere like the Elite 4. In most normal battles though I don't bother, since you don't need 'em.