Hey everybody, I have a quick update for those who want xBRZ-like quality from the Raspberry Pi. I ended up working around this by replacing RetroPie with Lakka, setting the full-screen resolution there to 1280x720 and using the 4xScaleHQ shader (in the scalehq directory). Everything runs smooth, tried with numerous games on various platforms, including MDK on PlayStation 1. No lag in the menus either, and the image quality is fairly close to xBRZ (though, of course, you can still tell the difference). I am quite happy with this solution. Another nice shader you can try is scalefx-hybrid.