As appealing as LuaJIT was and is, I could never bring myself to write much code for it. Even setting aside the possibility of Mike Pall giving up on the project (which turned out to be correct) the lack of a community around the language meant there would be difficulty getting questions answered and few third party LuaJIT packages. Bugs in particular were a major concern: if Mike Pall didn't find my bug report important, I'd be out of luck.
And as interesting as it is to have a small scripting language be able to run code so quickly, there are new languages that deliver the same benefits. Nothing really stands out about LuaJIT to make me feel it is a language I should use.
Bug reports with a reproducible test cases are often fixed and merged within hours. The craft, capability, and concern of Mike Pall has been amazing, even after he stepped down as maintainer.
My feelings are opposite. LuaJIT is here and now, and I won't wait for yet another community-driven python-or-rubylike that will [never] become its weak competitor.
Lua 5.1 itself is Scheme with regular syntax traded for macros, and one doesn't simply drop another language in for replacement.
The benefits I was referring to are being able to write fast, correct code easily. Other languages that allow one to do that include D, Go, Clojure, and Scala. If you want a scripting language, you're stuck with LuaJIT for now, but at least to me that's not an important distinction for anything I'd want to do with LuaJIT.
LuaJIT comes with warnings like "Callbacks are slow" and "The following operations are currently not compiled and may exhibit suboptimal performance, especially when used in inner loops:" which pushes it further down the list for me.
The vast majority of the time, swapping out Lua PUC with LuaJIT will result in code functioning the same but at least a little faster; often much faster. It's a pretty stable project.
And as interesting as it is to have a small scripting language be able to run code so quickly, there are new languages that deliver the same benefits. Nothing really stands out about LuaJIT to make me feel it is a language I should use.