Arguing the details of the issues between Ruwart and Barr is wasted typing and wasted breath.
If you must know Ruwart actually disagrees with Ron Paul on two major issues:
1 - Immigration
2 - Abortion
But that doesn't really matter. The issue details don't matter. Not one of them is going to be President. The best strategy is to support Barr for the nomination here. He is the only one who has a chance at getting the necessary media exposure to help continue the Ron Paul message. NONE of the others do.
Technical differences on the issues between these Libertarian candidates matter not one iota, unless you are married to the Libertarian Party. If you are married to the Ron Paul message, the clear logical choice is Bob Barr.
This is the one case where I will not make the effort of arguing the issue technicalities. This time it's all about answering the following question:
Which candidate has the best chance of continuing to spread Ron Paul's message of freedom, prosperity, and peace?
If you don't answer Bob Barr, then you aren't paying attention.
Enjoy.