this video really illustrates competence and experience.
At :15, Cain is completely frozen and confused by the question. You can't make a good decision about something when you don't have any experience in that, can't define it.
Newt, on the other hand, has probably 2 decades of legislative experience with this subject matter, and can not only define it, but gives us analysis and evaluation of various solutions.
It's not even close. Newt is a man who will embrace the challenge of tough questions and will call obama (in more professional words) a child who is in over his head. Cain can't do that. He's a good guy, he's likeable - but he will miss numerous opportunities to "gotcha" on Obama. newt will grin, salivate, and POUNCE upon those chances. Obama will give him the openings - and if the repub candidate can exploit them, Obama will sink. Newt will grab those - I don't think Cain can.
Cain - IMO he would be a HELL of a party chairman - A michael steele with balls who can MARKET the party better.
Newt would be a HELL of an effective debater against Obama. Cain will hope to hold his own.