AMA - Cost Seg Study

Today is another AMA episide (Ask Me Anything). Michael writes:

"Hey Victor, I have been investing in multifamily properties for over a decade, mostly in smaller deals but a few in the $1M to $2M range.  I've been encouraged to do cost seg studies many times over the years and cannot get the math to pencil out.  As an actuary by trade, I have a high degree of confidence in my analysis, but am wondering if I'm missing something or if this works in some cases.  Have you had any deals where completing a study made sense?  If so, can you explain why it made sense?"