Yeah, SpaceVim has lang#ruby layer, here is a guide: Use vim as a Ruby IDE. I do not use Janus, but I think it should works well, as the developers of that project also use ruby.
The full-GUI vim?
I am using gvim and neovim-qt.
If you are looking for another gui vim, maybe you can have a try with:
- fvim: https://github.com/yatli/fvim
- goneovim: https://github.com/akiyosi/goneovim