I play around with different variations of grip widths and positioning, and feel like there's a time and place for pure isolation or totally compound movements. If one area is significantly weaker than the others, it helps to work on that in isolation, and if another significantly stronger, you're probably going to be doing all of them a disservice and possibly risking injury.

Leg presses, delt flys, and lat pulldowns are some that I prefer to sometimes do in isolation to ensure that one side isn't significantly compensating for the other. I find that it's also a more effective use of the mental energy required, by reducing the total amount of muscles to pay attention to.