My two cents on Marriott choices in Beijing
1. Courtyard NW - good property if you need to be in this area. Staff etc are good, rooms functional, etc. No complaints but nothing outstanding.
2. Ren Beijing City - Plat upgrade to standard club floor room, no Plat recognition on check in, lounge is a little like a train station (very busy) although in fairness property was sold out. Rooms OK, rooms on street side (3rd ring) very noisy with traffic, I think the rooms on the front of the property (west facing) should be quiet. Good spread for dinner in lounge.
3. JW Marriott City - favourite of the bunch. Nice rooms, great staff, consistent Plat recognition on multiple stays, soaking tubs etc in health club. The Italian restaurant in the Ritz (adjoining) is great, although priced at Ritz prices. Buffet is best of three and IMHO better than the Fairmont. (Rooms and staff at Fairmont are slightly better, both are good location for CBD and subway).