FamilyTreeDNA has released an upgraded product from the BigY-500 to what is now BigY-700. This product does two important things; it is now capable of discovering new SNPs in regions of the Y Chromosome previously unreachable, and secondly, it provides at least two hundred more STR markers for refined mutation matching. To learn more about it please follow this link to Roberta Estes blog.
Here is an informative blog post from FamilyTreeDNA that discusses the benefits and genealogical advantages of Big Y testing. https://blog.familytreedna.com/2019-review-of-big-y/