Romney believes the economy is like a chia pet; sprinkle a tax break on it every day and watch it grow! Obama believes with proper regulation the economy will continue to gain momentum. Essentially you can choose between a plan we know doesn't work from past experience, or what is in essence no plan at all.
The truth is the economy and well being of the middle class involves a myriad of factors, many of which the President has no control over. The things that a President can do to make small influences on the economy, spending, taxes etc. he/she can only do with cooperation from Congress. So whatever promises they make are in vain, they can't snap their fingers and make things happen.
The only thing the President can do to directly affect jobs is hire/fire federal employees. Both candidates will do more firing than hiring, Obama will cost military and defense contractor jobs, Romney will cut social services jobs.
Every four years the country is on the brink of disaster, heading down the road to socialism or fascism, a welfare state or oligarchy; but ultimately nothing happens. When someone becomes President they suddenly have access to information and resources the rest of us don't have. This change results in a normalization of beliefs and behavior that lines up with the expectations of the Office. In other words the system is stronger than the individual, and it doesn't matter much who is in office.