of course NA can't see my post but looked up Vilas's H2H with Borg and on clay it's 2-11, Fed's vs Nadal is 2-12. I do agree Federer gave better matches though.
Also Vilas won the US Open on clay. Ok not red clay, but still a type of clay.
It really is deceptive to just look at the scorelines of Borg vs. Vilas clay-court matches. They played a very similar style and had epic rallies, it's just that Borg was usually a bit better at everything. This resulted in one-sided scorelines, but they certainly didn't feel like thrashings. Nadal and Federer do not have similar gamestyles.