Is the airport hotel you are referring to airside (transit hotel) or landside (Hilton, etc.)? If landside, I would recommend that you check your back to PEK only and collect your there since you'll have to take the train (after immigration) to the baggage belt/arrivals area anyway.

Not sure what you mean by "lost luggage" at PEK - haven't really heard of any occurrences unless there are irregular operations caused by weather.