Eh... I'm sure plenty of the RoboResearch UI code could be applicable to a RoboRunner frontend.
Just to chime in on the UI comparison. I recently came back to Robocode, and having been using the RoboResearch GUI in the past, I decided to try RoboRunner w/ RoboJogger. While I like RoboRunner's performance, I prefer the RoboResearch GUI over RoboJogger... but I think I'll end up going with RoboRunner CLI now, as I don't normally live in the GUI world anyway.