The second contains less characters and so is more compact to read. You don’t have to repeat myClass 2 more times, and the initialization logic is in one block.
It is really a syntactic sugar that doesn’t change a thing in the generated code. If you doesn’t like it, you can always disable the warning on ReSharper.
A longer post on the advantages of using Object Initializers here:
- Setting properties via object initialization or not : Any difference ?
- Is there any benefit of using an Object Initializer?