Only very rarely; my main camera, a Canon EOS 1D mk2n pre-dates this feature and my main interest is sports photography, and for that it's about as much use as a chocolate teapot.

Where I did find it useful was for macro work, with the camera on a tripod. This is using a Canon EOS 5D mk2 and the ability to zoom in on a particular part of the image @ 10x magnification to ensure critical focus is very useful.