Fully agree with previous posters.
Another excellent reason to do it is the cost.
In Australasia the cost is outrageous.
For example, a school in fort pierce, Florida charges $US300/hr dual on a beech duchess twin.
When it comes to time building, one can rent a single for $US130/hr.
The FAA allows hours to be logged by both pilots when flying IFR so if you file, you can split that and you end up paying half that.
Just check how the NZCAA consider those safety pilot hours.