Used Qantas CCs in USA in June/July. We each loaded UD8000 and GBP3000 . Used QCC as deposit card at hotel booking for 2 weeks, but had to change hotels after 1 day. Room far too small, hotel was very understanding and quite helpful. However later noted on iPad that QCC account had used up all the USD and was into the GBP due to pending hold on funds. A few phone calls back to Aus then we had to go back to hotel and get them to email QCC requesting release funds (which could be held for weeks). Eventually fixed and apart from 3 other cases of double entry, finished USA and converted residue to GPD then SGD.
Warning, use credit card for initial hotel deposit, then use QCC at end of stay.
Also note that USA don't let you use PIN but you sign the receipt; who knows what happens in the back room?
Otherwise the QCC worked well in all places and we both received the Q bonus points; but wasted a lot of time on the internet and phone.