For what it's worth, I'm working as a medical scribe and doing research at a medical school for my gap year. I think it's a good decision to take a year off if you feel your application is lacking in certain areas, rather than waste an application attempt. I had 2 years of chemistry research and around 400 hours of shadowing and volunteering, but there was plenty I didn't get to experience, like working in an actual hospital and getting that type of clinical experience. I also did a summer research internship in developmental neuro and decided it would be better for me to take the year off and continue the research from January '13 to August '14, really get some great lab experience in, and then send out my application. Taking a year off is very popular, just as going 4+4 straight. Do what's best for you.