Unreal.

The CryEngine certainly beats Unreal on the shiny shiny, but it has always been far too demanding of the hardware running it. Unreal manages to look nearly as good, but is far more customizable (as evident by how many more places it has been licensed over the years) and can run on more systems with a better performance.

That, and there's nothing like a twitch shooter to prove performance. A stealth centered-engine like the CryEngine just doesn't compare.