I just read a decent book on maximizing SS benefits. "Get What's Yours" was the title and it is a 2015 publish date. They heavily advocate to wait -- to maximize payouts. If you live well past 80, you'll be very glad you did (supposedly). They eschew simple "break even" analyses and point to actuarial tables suggesting if you live to 80 you'll probably live well past and would need the extra money. If you don't, then it doesn't much matter anyway. They also advocate to keep working. Other interesting tips and strategies.
I also have a few friends who retired a little early because of an incentive package. They don't admit to regretting the decision but they frequently comment on what huge difference it feels like when money is going out instead of coming in.
Last edited by dbg; 09-04-15 at 10:10 PM.