Seems one of Node's primary style advantages (async non-blocking style) has been eschewed.
One of the answers to "why node" question might be because it's all about Javascript. It's on the client, on the server, in the api, talking to the database...everywhere javascript. So node is a great choice for that. And it's very fast. I see luvit.io claims a 2 to 4 times faster than node performance, but it breaks the convenience of one language everywhere.
Lua on its own right, is a bit special. Fast, small, easy syntax - almost similar to Javascript when you think about it. However, "Coroutines in Lua are not operating system threads or processes. Coroutines are blocks of Lua code which are created within Lua, and have their own flow of control like threads. Only one coroutine ever runs at a time, and it runs until it activates another coroutine, or yields (returns to the coroutine that invoked it). Coroutines are a way to express multiple cooperating threads of control in a convenient and natural way, but do not execute in parallel, and thus gain no performance benefit from multiple CPU's. However, since coroutines switch much faster than operating system threads and do not typically require complex and sometimes expensive locking mechanisms, using coroutines is typically faster than the equivalent program using full OS threads."