I think the use of DNA to verify parentage in purebred cattle as well as check for carriers of defects and horn status are valuable information. If you do a full DNA test on a registered Hereford it tests for parentage, hypotrichosis, idiopathic epilepsy, diluter gene, as well as if the animal is homozygous or heterozygous polled. The diluter gene is a big one if your goal is to breed black baldy calves, if a Hereford bull carries the diluter gene there is a good chance you will get some grey calves instead of the preferred black baldy look.
Whether or not the use of DNA for GE-EPD enhanced testing holds any value is still to be seen. EPDs is just 1 selection tool to be used, they aren't gospel but it sure is nice if you can get both the desired phenotype and a good set of EPDs to go with it too.