There's been some discussion over on the Hilton board about modifications to the HHonors conversion partners & rates -

Now you can convert HHonors points to RR credits directly: 10,000 HHonors points = 1 RR credit.

The other options (besides actually staying at the hotel and making your 'double dip' = 1/2 RR credit) are still there - 85,000 for a r/t award and 350,000 for a CP. Those are obviously better deals (esp if the CP is really 100 credits and thus gives you 6 free round trips), but the new single credit conversion is another option to 'top off' an account if you're really in need.