Mario Kart 8 Deluxe has been rightly criticized for not offering new Grand Prix courses, but the improved visuals have not been fully appreciated.
MK8D runs at 1080p 60fps at all times when in TV mode, even during four-player sessions. This is a significant upgrade from the Wii U edition's 720p resolution with variable framerate (60fps single player, 30fps effective in multiplayer). I believe the Deluxe remake also has improved visuals through better lighting and effects, which are plainly visible in previews of the game. With the other new features (new characters, battle mode courses, driver assist, and portability on the Switch), there's a lot to like about this remake.
However, given the lack of new Grand Prix courses, I believe that owners of the original game should be given a $10 discount through My Nintendo, or they should qualify for free DLC (if any DLC is eventually offered).
Discussion started at here by el47000