I disagree. There are huge differences on foreign policy, abortion, tax cuts, gay rights, gun control, property rights, state rights, and national defense, to name a few.
You are right that there are differences, but unfortunately the score card no longer tells you what to expect from a candidate. Ever since the GOP bought into the "big tent" theory, the philosophy has been diluted to the point of being almost meaningless as a platform to be adhered to and defended. TPTB in the GOP are happy with big government, so long as they are in charge of it. And that frustrates me immensely.
Sometimes I let my frustration carry me away and I overstate my position. (But don't tell anyone. I use that in negotiating. LOL)