C#, unlike GDScript, has full and strict typing and order in the code and enumerations, and there is enough functionality. (With the documentation, everything is OK for both). In addition, C#+Godot, unlike GDScript+ Godot, normally and fully support all popular IDEs.
On the issue of performance, I’ll just quote the developers : “According to some preliminary benchmarks, the performance of C# in Godot — while generally in the same order of magnitude — is roughly ~4× that of GDScript in some naive cases. C++ is still a little faster; the specifics are going to vary according to your use case. GDScript is likely fast enough for most general scripting workloads. C# is faster, but requires some expensive marshalling when talking to Godot.”
