A couple of weeks ago the details of Hilton’s first quarter 2013 promotion were leaked, which would run from January 7 through March 31, 2013. Anyway, registration is now open for the promotion, and you have the choice between double Hilton HHonors points and double airline miles for the duration of the promotion. Unfortunately there’s a long list of non-participating properties, so be sure to check that out when planning your travel.
You must register prior to check-out of your first stay during the promotion period, and you can’t change your selection once you’ve registered, so choose wisely.
Typically if most of your stays are expensive/long you’re better off choosing double points, while if your stays are cheap/short, you’re better off choosing fixed miles.