Menyoo offers a much broader variety of options and room for creativity. The server only has select emotes in comparison to Menyoo, which has literally thousands more. There's also the option to freely move your camera around. If only Rockstar Editor compatible with Rage MP!
I personally do not see the problem with taking content using Menyoo, I have done it a whole lot myself for my character. It does get weird when people say they own something they do not, but I have only literally seen one case of that happening. Either way, it's not harming me if they do, it's never going to affect me or my roleplay.