As far as I understand, Luna should currently be best seen as alpha/beta-grade release, mostly aimed at Early Adopters. I see it as a revolutionary technology, and I am totally a good example of this target audience (been there, done that, w.r.t. e.g. Google’s Go language). Since I learnt about Luna’s existence a year ago, I was dying to get even such rudimentary access to it, and now I’m much happier I can already learn it and (if time permits) contribute.
That said, as far as I know, improvemets to the performance are totally planned, and I believe they’re exactly the next main goal for the project. That said, the team is small and the job is not easy, so it will take them time. I seem to have read a somewhat faster version may happen around summer, though personally I suspect it may well slip to winter.
Also, they totally are happy to accept contributions, including bug reports on github!