Performance is generally great and if you need to, there are lots of features in the language to allow you to further squeeze performance. C# is easy to pick up and has best-of-breed IDE support- you will get productive quickly. Also, you have an extremely large standard library at your disposal that is supported and dogfooded by Microsoft. Which is great because generally you do not need to install third party packages, but if you do NuGet is really easy to use.
Edit: Forgot to mention the stellar documentation provided by Microsoft.