"What curious eye doth quote deformities?"
-- Shakespeare, Romeo and Juliet
Act I, Scene IV, Line 31
I've started using Unquote for my assertions with F# xUnit tests. I find that its step-by-step failure messages really help in figuring out what is going on.
One thing that really throw me when I first used it was the System.MissingMethodException exception that Unquote was throwing at runtime. Luckily I was able to find this StackOverflow answer. It seems that you need to do a binding redirect for FSharp.Core, so you'll need to set up an App.config file in your test project like this example of the Coin Changer kata (using MapFold).