We have a rough idea of how Obama would bring about government control of private industry through Obamacare and Dodd-Frank. From Ryan's voting record, we have a rough idea of what Romney-Ryan would bring us: more of the Bush-era big government. In other words, Ryan is just another big-government Republican holding himself out as a fiscal conservative. Even his controversial budget proposals -- which the House approved, but the Senate declined to address -- would have increased government spending. It was less of an increase than Obama wanted, which is why the Senate Democrats refused to consider it, but it was not a cut in spending.
I am a firm believer that the Constitution means what it says. The federal government can only do what the Constitution authorizes it to do. The modern-day Republican and Democratic Parties have made a shambles of that principle. Nevertheless, I understand the "anybody but Obama" urge among those who fear his excesses, as do I. Obama has killed innocents, altered laws, rejected his oath to enforce the law faithfully, and threatened to assault the liberty and property of Americans he hates and fears.
Even though Ryan is a smart and humble and likeable man who was once a disciple of Ayn Rand on economics, as am I, the Republicans want the Bush days of war and spending beyond our means and assaults on civil liberties to return. The Bush years were bad for freedom; without them, we would not have had an Obama administration.
Which do you want?