Power = Work / Time

.NET Remoting performs as well as or better than DCOM? Binary performs better than XML? A Porsche 911 performs better than a Freightliner Truck? Yes. No.

"Performance" is an abused term. It's too often used as a synonym for "speed" and mostly in a completely unqualified and unquantified context.

Performance belongs on the left side of  power = work/time. In contrast, "speed" is simply operations/time. Difference: "operations" is about crunching machine code instructions, "work" is about handling application features.

To execute a remote call, .NET Remoting may be doing just as well (or a tiny bit better) than COM-transport-tunneled serviced components in absolute time -- but there's a lot less work being done by Remoting: context propagation, authentication, authorization, signature, encryption, etc. are things that COM does on top of what Remoting does.

Conversations using protocols that carry binary data are faster than conversations carrying XML in absolute time -- but there's a lot less work being done and the benefit of that work are interoperability, extensibility and enabling of the virtualization of system and network services.