So a common workflow of mine is that if I'm downloading a video file, I might start a manual extraction while its in the process of downloading and view the file in vlc.
winrar will pause when files aren't available and I can continue it when they are downloaded. Now, if it downloads faster than vlc plays it (And I dont forget to continue the extraction), I can quickly view the file and dont have to wait for the whole thing to download.
A side effect is, when it finishes downloading, newsbin can't extract it, so leaves all the rar files there. Back in 5.x I was able to click a single button to delete them all, but that functionality is gone in 6.
On a similar note, it be interesting to support the functionality I described directly (namely to extract on the fly) and just delete all the files at the end if the extraction was totally successful.