I look at SuperLuigiU and disagree.

Why? Would be just as perfect. New Characters, stages and game modes!

Despite my overall views on DLC, Mario Kart's just too good to pass up something like that, especially if they're of the same quality as the current tracks.

Oh, well. I'll change my DLC views just for Mario Kart.

I second this. I am not a big fan of DLCs in general but for a game like MK8, A high quality DLC would fit perfectly...

Off course, It would depend on the quantity of content vs price...

But the two games have a structural difference in how they're played. The tracks are the value of a Mario Kart game. One cup can give you hours of playtime that holds near unrepetitive value. On the other side, no matter how much you may love Mario Kart, if you were restricted to just one or two tracks, but like 100 characters, you'd get bored fast. In smash, that isn't the case. The characters are what hold the value. The stages are secondary.

Unfortunately with Smash, the stages don't really matter. You can get hours of satisfying gameplay from Smash just from playing Final Destination and Battlefield. It's the same way with all fighting-style games. But because of the nature of tracks vs. characters, added tracks have more monetary value. 16 new tracks means that you're adding 16 tracks to all the other tracks you will already be playing. In Smash, if you get new characters and you don't like them, you'll just never play them because they're expendable. Unless the DLC was free, it would be a cheap sell rather than hours of added content like with a full new cup.