Positional sparring is a fantastic way to sharpen your execution of a technique. Way more important than Free Rolling and that's not just my opinion. It's the opinion of practically every single world champ or Gracie family member I have ever interviewed.
For those not familiar with the term positional sparring: The instructor introduces three triangle fundamental escapes (for instance) then you drilled them in isolation (against progressive resistance) and then you roll, but every roll started from inside your partner's triangle set-up position. This is an excellent way to learn fast and learn well!