When do they take the money?
A few bookings I've made recently on rates that require a deposit -
Bradford Hilton: taken within 24 hours of booking
DT Leeds: taken two days before checkin
DT Newcastle Airport: taken about a week before checkin
Hilton Glasgow Grosvenor: not taken until checkout via card swipe done at checkin
I stay regularly at the Grosvenor so I'm not sure if it's because I'm a regular and trouble free guest (usually with nothing on folio too) that they didn't charge before I arrived.
All reservations tend to go straight to the hotel front desk, I think, and it's up to the individual hotel to then debit you at their convenience.
Hilton seem to be very trusting; I take advantage of a lot of discounted rates too.