Actually Nadal beat Federer on Rolan Garros final only 3 times, he beat him once at Wimbledon and once at Australian Open, so on all 3 surfaces, as for Federer he only beat Nadal in finals on grass. The level of competition is higher now than in Sampras era? That era you had the claycourt specialists - Bruguera, Kuerten (who, let's not forget, beat Federer at French 6-4,6-4,6-4 on 2004, a year when Roger won all other 3 majors) and the grass specialists - Ivanisevic, Becker, Krajicek and you can add a Rafter or Agassi. How about now? 3 (THREE) years running same players reached the final at Roland Garros and Wimbledon!!! So you either have those 2 as the best players ever or the competition is very poor.