Quark has failed to match LINQ performance consistently, let alone exceed it (surprising considering enumerable overhead).
I will be dropping the project for now, and releasing this code to the Public Domain (BSD-3 => Unlicense).
Quark is a high performance drop-in replacement for the .NET LINQ library.
Click here to see docs, articles, benchmarks, etc.
Quark does make a few small changes for performance, but its still worth it to go over our changes page.
TODO: PUT PRETTY GRAPHS HERE