The main advantage of the SR-parser is that it can train and parse documents in almost linear time (regarding the document length), while the CODRA parser needs cubic time.
for example, in the very popular corpus -Rhetorical Structure Theory Discourse Treebank (RST-DT) (Carlson et al., 2001) which contains 385 documents, the frequency of "Elaboration" is 31.04%, while the frequency of "Summary" is only 0.88%.