I believe points work better.

Of course, it depends on what you cash them in for.

My wife and I like to stay at Camelback in Scottsdale.

Right now, you can get a room for $149 per night, or $209 per night including breakfast and spa admission.

During the winter, you would pay $400 - $600 per night for the same room.

So we pay for the summer stays with cash (credit card) and use points for winter stays.

On a similar note, it depends on what you use your miles for.

United "charges" 25,000 miles for a domestic coach ticket. I calculate that the miles are worth 2.5 cents each. So a domestic coach ticket would "cost" $625 if you used your miles. Why "spend" $625 in miles if you can buy a coach ticket for $200 - $300??

On the other hand, international first class costs 125,000 miles of $3125. An international FC ticket would cost $7000 - $9000. So it's a good deal to take $3125 worth of miles and use them for a $9000 ticket.

From Marriott, take the points and use them for some expensive property, not the Fairfield Inn in Coralville, IA.