Spot mode isn't just for post, I've always used it more than most music people and the way I introduce it to new users is by showing them how spot mode can solve a common problem.
When I started using Pro Tools I was using it as a tape recorder, recording musicians with no click and editing in Slip (the session's Grid was after all , unrelated to the recorded music). In this scenario, if I erroneously moved a clip, the only way I knew of to restore the moved clip to its original position was to revert to a saved version. Even then I knew that couldn't be the whole story.
The reason I didn't know how to restore a moved clip to its original position was because I thought Spot mode was for post and I didn't need it for music.
To restore a moved clip to its original position select Spot mode (F3). Select the clip with the Grab tool and the Spot Dialogue will open. At the bottom of the window is the Original Time Stamp. Pro Tools stores the start time of whole file clips in the file's metadata so this information moves with the file between sessions if necessary. The Spot window opens with the start field selected by default so just click the up arrow by the Original Time Stamp field and hit return and the clip will be restored to its original position.
Remember to to exit Spot mode or the next clip you click on will open the Spot dialogue again (this happens to me every time....)