The comparison we discussed was for unrepresentative code that used none of the features that make .NET fast (generics, SIMD, expected forms of inheritance and abstraction and devirtualization they enable, CoreLib APIs). The closest case in there was JSON serialization which CoreCLR was 385% faster at. It is unfortunate that you feel a need to say this, knowing that it doesn't even show a tip of the iceberg.
Please do not mislead casual readers here with such comments.
They will have a bad time running basic programs - the original Mono is outdated and cannot execute assemblies that target non-legacy versions, and the Mono that lives in dotnet/runtime (which you have to go out of your way to use on CoreCLR platforms) tends to have all kinds of regressions on user-provided code that is not as robust on runtime checks to ensure that Mono does not accidentally go onto the path that that it has especially bad regression on. Even CoreLib code nowadays uses more and more struct generics assuming monomorhpization which performs poorly on Mono. There is very little work done to improve performance on Mono with effort invested mostly in WASM area and to ensure it does not regress further. Major platforms like Android and iOS are in the slow but steady progress to migrate to CoreCLR/NativeAOT (there are other reasons not in the least much smaller binary size). And for WASM there is NativeAOT-LLVM experiment that is likely to make Mono obsolete for that target too.
The workloads that matter and are representative are the ones produced by C#, F# and VB.NET compilers as well as projects that care about exercising the standard library and/or produce recommended CIL forms (like https://github.com/FractalFir/rustc_codegen_clr).
