I think it really depends on the severity of the deviation and blockage. Before I I had the surgery, the difference between nostrils was significant. Left side was normal and the right was like breathing through a very small diameter straw. Post surgery, I sleep much better and rarely snore. I feel more comfortable when running or biking long distances while only breathing through my nose. Do yourself a favor and get an evaluation if you have a blockage or deviated septum!