Put it this way. If you score a 700 or greater, you will be in range for schools like Columbia, Kellogg, Booth, Sloan, etc (not a shoe in, but still enough of a shot that they're worth shooting for).
So it comes down to how confident you are in getting that score, and whether you're willing to wait another year for it. That's entirely a personal decision. As for whether going to Smith is worth it or not, what I suggest is visit the school NOW while class is still in session - get a feel for what the students are like, and whether you feel you'd fit in there. A simple visit and interaction with some of the current students should make it clear to you whether it is worth it for you or not.
Thanks for the feedback Alex - I'll do whatever is necessary to achieve that 700+ and have signed up for a GMAT prep class to get me there. I feel you don't have to be MENSA to ace it, I probably just studied incorrectly or not enough the last time. I'm also considering signing up for summer classes at a local university in stats or acct'ing (bleh) to show the adco's that I'm not a slacker like my undergrad GPA shows -- would you recommend that or is it too late and focus my energy on other activities (e.g.: extracurriculars, LEED accredition)?
I visited Smith and spoke with alums, students and the faculty -- I don't feel it. Maybe it's because I have already made up my mind or maybe it's not the vibe I'm looking for. Either way, it was a mistake in applying and I'm not going to waste more time considering it when I could be utilizing that time on improving myself.