There was a quick moment of laughter, when Obama referred to first lady Michelle Obama as "sweetie" and noted it was their 20th anniversary.
Romney added best wishes, and said to the first couple, "I'm sure this is the most romantic place you could imagine, here with me."
Both candidates' wives were in the audience.
Without saying so, the two rivals quickly got to the crux of their race — Romney's eagerness to turn the contest into a referendum on the past four years while the incumbent desires for voters to choose between his plan for the next four years and the one his rival backs.
Romney ticked off the dreary economic facts of life — a sharp spike in food stamps, economic growth "lower this year than last" and "23 million people out of work or stropped looking for work."
But Obama criticized Romney's prescriptions and his refusal to raise taxes and said, "if you take such an unbalanced approach then that means you are going to be gutting our investment in schools and education ... health care for seniors in nursing homes (and) for kids with disabilities."
Not surprisingly, the two men disagreed over Medicare, a flash point since Romney placed Wisconsin Rep. Paul Ryan on his ticket.
The president repeatedly described Romney's plan as a "voucher program" that would raise out-of-pocket costs on seniors.
He continued, directly addressing the voters at home: "If you're 54 or 55 you might want to listen because this will affect you."
Romney said he doesn't support any changes for current retirees or those close to retirement.
"If you're 60 or 60 and older you don't need to listen further," he said, but he contended that fundamental changes are needed to prevent the system from becoming insolvent as millions of baby boom generation Americans become eligible.