I am also concerned about the quality of the tooling. DNX can't handle long paths so I have to develop out of C: drive. This reminds me of Node's almost incompatibility with Windows and makes me worry that the tools haven't been thoroughly tested. DNX is going to be replaced yet again in the near future with a newer, probably less tested set of tools.
On top of that the tooling doesn't work well in enterprise because they have poor proxy support. I'm also worried about "everything is a collection of hundreds of tiny packages", the NPM dramas have shown us that micropackages lead to insanity. ASP.NET was a place to hide away from those kinds of things. Now it feels like it's "C#, as developed by the node community". I think they've tried to make things simple but haven't seen the forest for the trees. The fact that they're bundling dead tools like Bower into the project templates is also worrying. They should have had the forethought not to include any JS libraries that have a high churn rate.
One final thing bothering me is the number of choices of the target framework. Why have there been so many meaningless names like "dnx451", "netstandard", "netcore10"? I sit down to make a web app, and I have no clue what I actually need to target. In the old days we'd pick a .NET framework version and choose either the compact or complete framework. When did this become rocket science?