For me jruby is a lot more accessible, so I have been using jruby rather than TruffleRuby. GraalVM is pretty cool though - I don't quite feel it is 100% "ready yet", even if you can go very far with it (statically compiled binaries on linux worked well for me). Some things have a low priority such as swing-support; some got it to work, others did not. I understand that swing is legacy, but still it works out of the box, so IMO it should be supported too. It is only semi-supported and I think this is a problem with some of GraalVM, at the least with fewer-used parts of it.

I feel that this semi-friendly competition between the two projects is not good. I also understand neither wanting to "adjust", and in the process lose options; in particular if jruby would be assimilated, we may run the possibility to have jruby work as-is, without necessarily being tied to e. g. the larger java ecosystem. I use both ruby and java, but being able to function in a smaller way, is an advantage (for ruby; see also mruby). Nonetheless I think both projects should eventually curb down on their ego and present a unified java-centric ruby variant that includes all options that existed BEFORE that. Merging by losing features would be stupid - but remaining separate also is stupid, IMO.