There exists no international standard in how hotels are rated in terms of how many stars it deserves. In our trip just ended visiting 8 different cities in Japan, Hong Kong, Macao, China, Cambodia and Vietnam and staying in 11 different hotels (2 of which, including Caravelle, were rated "5 Stars") in the duration, my wife and I were in a position to rate Caravelle vis-a-vis all the others we stayed in on this trip... and we have to say that Caravelle is not 5 Stars. I would say it's closer to 4 Stars and, in fact, was not as good as some of the 4-Star hotels we stayed in on this trip.
So what were the problems? As I said at the beginning, there are no standards to the hotel star classification system but Expedia and Travelocity describes 5 Stars as being luxurious, highest comfort and superlative/flawless guest services. This does not describe our experience at Caravelle.
Firstly, the thermostat in our room was faulty which made the room either too cold (because the A/C was on all the time) or too warm (when we had to turn off the A/C because it got too cold). We complained to the front desk, the staff were courteous and said they would look into it.
Next day, no change and we complained again and they sent a guy to our room to fix it. He pretended to fiddle with the thermostat switch for a few seconds and then said it was fixed! I said you didn't do anything, but he insisted otherwise. Needless to say, he lied and we had another cold night. We complained on checkout and they said they were sorry. I'm sorry, but just simply apologizing doesn't make it better given the 5-Star hotel rate were charged.
The room itself was average size, not big unless you're comparing to a 3-Star Tokyo hotel. The bathroom faucet was leaking on our first night but that was fixed by the next day. The hotel had all the facilities such as a spa, workout room, pool, restaurants, etc. Breakfast was very good. I tried to go to the business center to read a newspaper but the staff there said it was not possible. I think they just had fax/photocopying machines in there and not much else. Sorry, it's not a business centre.
However, at the end of the day, the hotel room was not comfortable due to the A/C problem and, other than saying sorry, Caravelle staff did nothing else to resolve the situation.
Caravelle is a solid 4 Stars in my books. If you're looking for a real 5-Star hotel, nearby Park Hyatt may be a better choice.