[wvenable]

It doesn't seem that bad -- the lack of readonly would be my only concern out of that article and one I didn't actually consider.

I think, as a feature, this is sort of the MVP. They could have done a better job of it by adding more to it (e.g. maybe allow the readonly modifier on the constructor properties). It's hard to imagine them being able to take anything away from primary constructors that would make it better.