We loved the JW Marriott Beijing. It is not as conveniently located to some of the attractions as some hotels but in a way, that's good. Most areas of the city we found to be so crowded that it was nice to come back to the JW and get away from the throngs. The hotel is a two minute walk to the metro line and it is dirt cheap and you can get anywhere in the city by transferring. It is clean and easy to use, but also crowded during rush hour.
We are Marriott Elite members and were eligible for their Executive Lounge which was wonderful. They provided a plentiful breakfast every morning (or you could choose the buffet in the restaurant free of charge instead), dinner, drinks and dessert every evening. The service in the Lounge was wonderful. It was nice to have since wine is very pricey in Asia. We saved a lot of money.
The rooms were very comfortable although there was no upgrade available so we got the basic king room. The bed was very nice, bathroom was well appointed (although I'll never get the glass bathroom wall thing), and the internet worked well. We tried the Friday night seafood buffet and there was nothing that wasn't on the buffet. It was about $60 US including wine.
It was typical great Marriott service and comfort, we enjoyed it very much.