Dependency Injection and AOP frameworks for .NET

We're looking to implement a framework to do Dependency Injection and AOP for a new solution we're working on.  It will likely get hit pretty hard, so we'd like to chose a framework that's proven to scale well, and operates well under pressure.

Right now, we're looking closely at Spring.NET, Castle Project's Windsor framework, and Unity.  Does anyone have any feedback on implementing any of these in large, high traffic environments?