We aren't arriving late or leaving in early hours (this is actually the reason I chose to try Air China for the very first time). For us, because we have a toddler, I am very concern about the sanitary condition in some PEK hotels I have found on reviews.
For those of you who did not take the complimentary transit hotel, did you try to have the airline reimburse you? If the assigned hotel is really terrible, we may have to go somewhere else on our own. That would be the last resort for us.