It is a blast to work with LINQ and Lambdas and I really miss it in other languages. EF Core also matures quickly and we sucesssfully connected it to mysql and sql server. So far there hasn't been a problem we couldn't solve in .Net Core.
For a small side project I used .Net Core Razor Pages very productively. Only needed the SDK and visual studio code. Planning on moving more small stuff away from python to .net core based on that.
Really looking forward to Version 3.0 and Kestrel replacing IIS for good.