The Disclaimers
1. I am a n00b. blehhhhhhhhh. I guess I was among the youngest people involved behind the scenes (possibly the youngest).
2. I have never been to DC Proper (Las Vegas), so I can't compare it to "what DEFCON should be."
3. Mess. I am one.
Venue
The venue was appropriate in size and facilities. The rooms were nice, although getting wifi access in the upper floors without a pre-set burner/online access/second sim number was next to impossible. !!Unless you're Zoz, who managed to use the phone number of a random hotel worker as his own to gain access (Zoz is great though, seriously). !! Consider getting multiple VPNs prior to arrival and make sure they are accessible without external connection requirements for the best performance. If you cannot find such an option, get your own wifi spot.
The piano downstairs is horribly out of tune and has sticky keys, but it looks pretty. Speaking of pretty sights... Views on the convex of the hotel host plenty of greenery and smog. Views on the concave side have a cityscape that looks sufficiently like a dystopian under-lit electronoir dream. Also smog.
There is a terrace, but I never saw anyone ever attempt to go out there. Probably because of the smog.
There is a lot of smog.
Activities and Atmosphere
Compared to what I've heard of DC LV, this version had very limited activities and a more academic feel. To be fair, it was also about 20-25 times smaller than the Vegas version. Labs were the only "official" event type that was missing, and the CTF setup was great - visually and everything (seriously, it was great). Unofficially... there was a significant lack of parties and disorder on behalf of the attendees. The staff had their own fun though, heh, and at least one machine was torn apart, so that's something.
Since this was an international trip for most of the staff, there were a lot of touristy activities, but I'm not sure these would be available for "human" badge holders. In any case, you can do these things on your own.
Cost
I have no idea what the badge cost was, so I can't comment on that. The hotel venue is fairly expensive - it is a 5 star hotel so... - but cheaper options are available within a km or two. Think on the range of 360rmb vs 1300rmb per night, not including the deposit (which varies on stay). A hostel closer to downtown will cost about 90rmb. A taxi ride downtown (make sure to use the DiDi app and activate it PRIOR to landing in China, avoid the red light cars: these are gypsy taxis) will cost about 50-70rmb, and food at a nearby food court will run around 20rmb (however, food at the hotel will be considerably more expensive). If you prefer the subway, there is a stop 4o0m away from the hotel (Wangjing East), and a single ride will cost about 5rmb.
Other Comments
1. Police and security are stationed throughout. They are separated into the "suits," the riot police, and the ones who dress like casual attendees.
2. Surveillance is constant, although no more so than at a Vegas casino. Just imagine that constantly.
3. There are some fun activities that you need to find your way into - but asking people about them might end up slightly on the negative side, especially if the people you ask are in no way affiliated with DEFCON.
4. Baidu is a good host, but you do have to follow and meet their expectations. Enough said.