I’m all in favour of C# (and Skookum), but I really recommend you guys to take look at Haxe for Unreal plugin: GitHub - proletariatgames/unreal.hx: Unreal.hx: Haxe Integration for Unreal The plugin has really fast compile times and hot-reload.
I’ve been writing Haxe (http://haxe.org/) for many years (used it for html5, flash and mobile games) and I really recommend it to everyone - it has tons of really powerful high-level features and the best macro system I have ever seen.
You can play with the language and try out different examples here: http://try.haxe.org/