I maintain a JRuby-based app. I looked into TruffleRuby a number of times but faced issues each time on that code base, so I could not get to the point where I was able to compare anything. YMMV!
Just curious, what issues did you encounter? With JRuby being a fairly well supported community project, most gems just work out of the box with it, so I'm curious how the other implementations deal with things like gem compatibility etc.