LuaJIT performance on PC is very fast when its using the JIT. However, on consoles and some mobile platforms JITing is not allowed due to not being allowed to write to executable memory for security reasons.

Mun compiles to machine code with LLVM so it should be very fast as well, hotloading overhead can be completely removed in builds where hotloading is not required (production builds for instance). Mun should therefor be able to run as fast as native code on all platforms.