Is Entity Framework 4 a good solution for a public website with potentially 1000 hits/second?

In my understanding EF is a viable solution for mostly smaller or intranet websites, but wouldn't scale easily for something like a popular community website (I know SO is using LINQ to SQL, but.. I'd like more examples/proof...)

Now I am standing at the crossroads of either choosing a pure ADO.NET approach or EF4. Do you think the improved developer productivity with EF is worth the lost performance and granular access of ADO.NET (with stored procedures)? Any serious issues that a high traffic website might face, was it using EF?

Thank you in advance.