Um, they are both "more important". This kind of question is not useful. The entire process is important, or they wouldn't make you do it. You have to realize that med schools are getting as many as 10,000 applications, and are doing what they can to separate the wheat from the chaff. As a result, it only takes a bad PS or a bad secondary essay to give them the ammunition they need to weed you out. So it is all important, the grades, the MCAT, the LOR, the essays (both PS and secondary), the interview, and so on. It is foolish to take the approach that you can work less on one part of the application. If you don't have time to do a good job on the secondary, that's a problem because you'd better believe the other ten thousand applicants applying to that school found the time. So no, there are no lower expectations. You give 100% on everything or you wait for a later cycle where you will have time to give 100%. This isn't a process where excuses count for much.