Cool, but much less useful than the full suite of Spring projects (which is why I love Spring in the first place, it's basically batteries included but everything remains modular so I can pick and choose what I want). .Net Core is a great stepping stone, but between deployment headaches (I can just run yum install java-1.8.0-openjdk to get a JVM and run a spring-boot app, .Net Core forces me to bundle the runtime right now) and the lack of a cohesive integrated suite of components keeps my heart with Spring (even if I'm forced to use .Net at work more often than not).