I know, miss Soderling, the greatest boomboom on clay. Soderling vs Delpo is one matchup I always wanted to see in RG, Soderling vs Berdych was pretty awesome.
Almost happened in RG 2009.
Think Delpo would win though such a match-up (and would have won a potential RG 2009 final), he usually overpowers the other big hitters. Slow surfaces really favor him vs big hitters since the rallies prolong and he'll ultimately overpower them most times.
Tomas beat him on Saturday by finishing points soon. In a slower surface, rallies would have been longer and Del Potro would probably have ended up winning in straights as he usually does when he faces a fellow big hitter.
Guys like Berdych and Soderling really thrive on fast surfaces, since their games are based on hitting lines/corners and finishing points early, it's clear how much better they become when they can hit through the courts as easily as in Madrid. On the other hand, their chances of success are greatly harmed by the scarcity of fast courts on tour at the moment. If I remember correctly, there were only 15 rallies over 10 shots in the Tomas vs Delpo match on Saturday and that's why Tomas won. Few can hang with him (and Soderling too) in surfaces that reward aggressive, first strike tennis.