I'd think that if you did something life experience-wise during your hiatus (like travelling, volunteering, working in a certain field), you should play that up when you apply, it doesn't necessarily have to be a mark against you. Also, it depends on what you did once you came back to finish up your undergrad - i.e. did you volunteer in a lab, work as an RA, do any research, work at relevant positions etc. I did most of my really "hard-core" building up of experience and qualifications during my last 2 years anyways, and that's what the majority of programs look at.