15 Year vs. 30 Year Mortgages on Rental Properties

[Ryan Denman]

In my market (Denver metro) properties are pricey and the amount of money that could be saved on interest for a 15 year vs 30 year mortgage is significant.  I am thinking that properties here would be best utilized by leveraging equity in them to buy more properties, and the 15 year notes would also help with that.  

I am also looking at properties out of state (less than $100k), and think that going for high cash flow there with 30 year notes would be best.

What are the prevailing opinions out there about 15 year versus 30 year mortgages on rental properties?