I second the call of bullshit. Though I've only skimmed the paper, I don't see any concrete performance numbers. I only see this:

"The group has written sev- eral million lines of code, including: core libraries (includ- ing collections with polymorphism over element permis- sions and data-parallel operations when safe), a webserver, a high level optimizing compiler, and an MPEG decoder. These and other applications written in the source language are performance-competitive with established implementa- tions on standard benchmarks; we mention this not because our language design is focused on performance, but merely to point out that heavy use of reference immutability, includ- ing removing mutable static/global state, has not come at the cost of performance in the experience of the Microsoft team."