When I read up on the Post Stack Depth Migration method of...

When I read up on the Post Stack Depth Migration method of seismic processing, it sounded to me like it was more appropriate for simpler structure models without dips or lateral velocity variations, as image quality is just as good as Pre-Stack in such circumstances. Apparently you go for Pre-Stack only for more complicated structure models with large dips and strong lateral velocity variations, as it’s far more time consuming and expensive but necessary to produce similar image quality results. (Also, depth migration is superior to time migration methods but warranted if you think you are onto a winner.) Google it.