I don't have a strong opinion about this. I don't think having applied once is going to hurt your application much. Some of the schools that you are applying to for the first time might have the question of why you are applying there this year, but did not last year (i.e. are you their 2nd/lower choice or do you really have a good reason for wanting to apply there?). I would say that for your interviews, just have a good reason why you are interested in each school you are applying to.
Since you applied late last year, you already have one "excuse" about why you didn't get in last year. It sounds like you are at least in the range of folks who get accepted, in terms of your academic profile, but you are not a shoe-in. Just focus on making your application the best you can in all ways (i.e. LOR's, your volunteer work, the way you sell yourself and your extracurriculars in your application) and apply early. Have some other people read your personal statement to see how it comes across.