If you had to design a Greenfield solution for a Wireless Network, with 2,000 Potential Access Points in a Hotel, Open Space Indoor, Outdoor Campus Environment. What vendor would choose?
Xirrus They are designed for a lot more users. The XR630 I've tested is Maximum Associated Users
240 (120 per radio). or you can get a few of their even bigger arrays that have several APs in them.
Xirrus is undefeated when it comes to hi-density APs. They build APs with 32 radios in one device! If I were needing something for a convention center Xirrus is exactly where I would go.
There are a couple of Ubiquiti deployments with over 2000 APs deployed.
You should most certainly entertain Aerohive. I manage a large, multi-campus Aerohive solution with exactly the environments you are describing (except its not a hotel) and it works fantastic.