The Good
It effectively reduces the background in the tissues, allowing a better staining.
The Bad
It may quench the antibody signal if too much exposed.
The Bottom Line
In the periphery of some tissues the DAPI staining can be quenched. Also, when using TrueView without DAPI counterstaining (the product that does not includes DAPI in the mounting media), DAPI staining will fade with time.