The speed of execution, ability to parse expressions quickly without having to write your own parsers from scratch or use existing frameworks that require you to rewrite everything in C#/VB etc., which can be very time consuming especially if it's not something you're familiar with already.
I also like how easy it was to get started using this library - just add an assembly reference in Visual Studio (or install via NuGet) and start writing code! Nothing really at all as far as any issues goβ¦