alt Hacker NewsGood review, but I frankly don't see the point of Result<T0, T1>. Just have the error be an exception type as exceptions idiomatically represents errors in .NET. Then you're down to only 1 type argument which is much less noisy. That's what I've used for the result type in my library that I've been using for years. I don't use it often, but it's very handy when appropriate.
If you ask yourself what the meaning of the word 'exception' is and then consider how many failures are exceptional, then one quickly realises that exceptions are the worst thing you could use to represent expected failure conditions.
The only time we should throw (or even pass around) exceptions is if there isn't a slot in the co-domain to inject a value in to.