I only use it on words or phrases that need it. I'll snip the line (I'm a Nuendo user), go into Automatic mode (Chromatic), and then Preview so I can watch the piano and see what's going on with the notes. I'll find which note he's hitting wrong and mute it out, along with the unnecessary notes either above or below it (depending on where I want it to go). Then it's just a couple of quick tweaks to the Retune and Choosiness, print, and DONE. With practice all of this takes less than a minute.
I also find AT VERY handy on guitar solos with pitchy bends...
-Lance