In Rider 2017.2 EAP, we did quite some work on code completion.
.csproj and XML files, more and better suggestions are now available.
Multi-line code completion has been improved, too — including import completion in C#. (tip: use Shift+Alt+left mouse click to set multiple text carets)
When generating code (Alt+Insert in the Visual Studio keymap), for example when generating overriding or missing members, Rider now shows descriptions of overridden methods, event handlers, Unity’s magic methods and some other items when they are available. This will help provide extra contextual information when letting Rider generate code for us.
Please download Rider 2017.2 EAP and give the new build a try!