1.55k nodes, 250k containersed applications[0].
Mind you, it's hard to compare these as there's no real "cloud bench". For pure benchmark porn Nomad are the undisputed champs on their 1 million case.
The Cloud Foundry scaling test was intended to show a system with fully service-configured, fully-routed apps, with varying app characteristics (memory and RPS). To further stress the system, thousands of apps crashing and are relaunched on a continuous basis.
Cloud Foundry installations with >10k containers have been ordinary for a while now; the 250k thing was to ensure we had lots of headroom and shake out chokepoints in Diego.
[0] https://content.pivotal.io/blog/250k-containers-in-productio...
Disclosure: I work for Pivotal, the majority donor of engineering on Cloud Foundry.