Best of the Best
There is nothing better than gut, and VS is the best. There are a few more choices now, all looking like, stringing like, and almost playing like, but nothing beats the best. The only con is durability, which is why you should protect the most expensive gut on the market by using "string-a-lings", most especially if using 17, or 18 gauge string. Hybrid stringing is the big thing now, so indeed use VS for the Mains, not the crosses. Almost any string will perform better with VS as the Main string.
If it's good enough for Federer, should be a good choice for anyone else.