Good poll, although from my experience it all depends on how many problems you do. For example, if you limit yourself just to OG problems, perform decently, and move back and forth through the book, it is hard to improve. When I focused on OG my quant was 37 and verbal around 29 even though I had a rather high hit rate of correct answers. However, after using other sources for practice I went to 48Q and 40V and I still improve quickly.
If you go through a large volume of problems, including those unrelated to OG, chances of forgetting correct answer increase a lot. Thus, if the person doing the problem improved due to practice he or she will be able to get it right and improve.
To sum up, learning from mistakes would most truthfully apply if a person does not get a chance to memorize correct answer.