I think it's not polite, if you just want to show something cool you did you could create your own thread. You don't interrupt a street musicians and start playing in front of the crew just because you think you are a "better" artist or that your version of the song is cooler right? It's common courtesy.

On a side note, I looked at both codebases and even though I've already said that I wouldn't use either of them I have to say that I find rurbans to be somewhat messier and uglier so I have to disagree with you.