I have never had a hold, that I have noticed, put on any credit/debit cards at a Hilton.

But I have with a Westin (Copley Place) in BOS. Was staying for 8 nights and the morning after my check-in I got a confusing to me call from Amex saying, "You have gone over your limit". I called back and said no way, they said check with hotel, re hold, I did and hotel had put a hold on my Amex (Optima type). As it was I could not use my Amex for anything else and the hotel would not remove it. Fortunately I had another cc. Going back there in a couple weeks for another week long stay, will see what happens.

Although now that I think about it if a Hilton was to put a hold on my credit card I think I would have a problem with it. Having status I think that should afford you some trust.