It really depends on your use case. I write all my tight loop code in LuaJIT itself, rather than calling out to C. Lots of people use LuaJIT as the glue to highly optimized long lived and proven C code libraries.
The case for doing the glue in Lua is the fact that script is arguably easier to prototype in. So, depends on your particular application space. C can be a lot more error prone, at least when it comes to memory management, but this is a general argument for garbage collected vs not.
The case for doing the glue in Lua is the fact that script is arguably easier to prototype in. So, depends on your particular application space. C can be a lot more error prone, at least when it comes to memory management, but this is a general argument for garbage collected vs not.