Well, I have heard a certain wise AdCom member (@gyngyn) comment that an excessive amount of time spent on an undergraduate degree can be a negative. I would imagine non-trads are cut some slack in this regard. Perhaps if you ask ever so nicely, he can clarify.all together? 'cringe' 6+ years; again this was due to working so much and having no real life goals in my early 20's. I've heard worse, I knew a guy who flunked out of two different universities; went off to Afghanistan for 3 years and is now attending Wayne State Medical..
I think the biggest issue that can arise from this is a) poor decision making ie changing majors seven times and spending 3 extra years in college as a result b) not taking demanding courseloads. Someone who changes to pre-med late or has another reason for staying say 6 years is not necessairly at a disadvantage. Someone who wants to stay longer to get their grades up probably wouldn't be either(hell its just like a DIY post-bacc then). But someone who only takes 9 credits a semester and graduates in 11-12 semesters and has to take light courseloads to be able to handle the material will be at a disadvantage.