I have stayed at the Conrad and all the Tripadvisor reports are true - they are rather understated in terms of their luxury, but it is delivered well. Diamonds get free brekkie downstairs but their explanation of the menu is lacking in polish as their English isn't quite up to par. The Exec Suite is very nice overall, however the little slits on the wooden sliding doors into the bedroom (and they are little indeed), do allow sunlight/a little bit of sound to pass through. This is generally not a problem unless you're extremely prone to being woken up by the littlest bit of sunlight, which I am. The bathtub has a great view over the park outside, as does the living room. The living area is quite spacious, if a little oddly shaped (especially the bit where the curtains disappear to, almost enough space for a mini walk-in closet/wardrobe there). Huge TVs, what can I say... I was also presented with a fruit tray and a bottle of red wine complimentary. Very enjoyable.
The staff on the Exec floor can seem a bit overeager also, which is nice - but odd when you're the only person on the floor. I only ever saw three other couples there, throughout the entire one night stay I was there.
I paid *almost* top dollar for their Exec Suite and they allowed me a very early check in. Oh - they were a little hesitant in terms of check out time, however - and wanted to initially offer only 2pm late checkout. After some internal discussion, they allowed 4pm late checkout and had I been a bit DYKWIA, I am sure I could have wrangled 6pm. Hilton Beijing Wangfujing knows me as a regular guest and sometimes would extend 6pm to me, if required.
Overall, the location of the Conrad is the biggest 'issue', if you're wont to be in the Wangfujing area. It is very near the Sanlitun area, however - especially if you take a cab. It's a 13-15 minute gentle stroll from the hotel to Sanlitun via three back lanes. There's also a HaiDiLao Hotpot along the way (which is one of my go-to restaurants in Beijing).
What else? The pool there is fantastic. A bit odd to have a lifeguard/trainer of sorts staring at you the entire time you're swimming, as I was the only guest who was swimming anyway when I went. They even have a dryer that you can operate for wet clothes, lol. The showers are ridiculously complicated to use, especially the digital controls.
Last comment: The Presidential Suite isn't ready yet. I did ask repeatedly for a price/for a viewing as I do consider using them when I have more guests accompanying... they will need a couple more months.