no one in a prod environment would be fool enough to use an engineering sample chip.. not in a prod env. No way. ES chips are just that. Sample to test with. The earlier they are in the chain the more flawed they are and people who cannot afford cpu errors simple do not risk it.
Speak for yourself man. I run a full 42u cab stacked with ES CPUs.. E7-8860/70 ES, 256 - 512GB of ram.. They run stable, fast and they're a fraction of the price..