I agree that Romney is probably better than Obama by a smidge. However, you have to think about the consequences of a Romney election versus the consequences of an Obama election. If Romney is elected, you are stuck with him for 8 years - there is no hope of running a different candidate in 2016. Are you prepared to sign-off on Obama-lite for a full 8 years? I think I would prefer Obama to get another 4 years than for Romney to get 8 years. After 8 years of Romney, the GOP will be stuck explaining all the liberal BS they signed off on just to show support for Romney, just like they did with Bush. Medicare Part D, No Child Left Behind, and the various bailouts of 2008 are an albatross that it will take conservatives years to recover from.
I'm in a swing state, and I'm voting Johnson (unless I can write RP in - still haven't determined if that's possible). If Romney loses my state, I want to send a message to the GOP - the libertarian side of the party is growing and you are going to keep losing until you run candidates that can prevent us from voting Libertarian. Running these centrist extremists is just not going to work.