I always taught the "raise the nose, convert XS speed to height" technique, not because it was more efficient, but simply because it allowed the student to trim for the best gide speed as soon as possible.
This allowed them to concentrate on their failure checks, without too much concern for aircraft handling. Spending a minute or sow maintaining level flight, waiting for glide speed, seemed like a waste of time, while the "XS speed to height" thing gets them thinking about their glide speed immediately, and it covers all situations.