I like the ideas put into these re imaginings of SMK maps. The vanilla SMK ports always felt too close to their original counterparts to be as fun as they should be, and some of them are more annoying in the long run. I prefer ports that try to mesh themselves within the games they are transferred into, rather than stay as they were first designed.
I like the item panels as a call back to SMK, and nearly all of the maps are fairly flat it is easy enough to see them coming. I like how Mario Circuit's shortcut closes on the last lap to prevent cheesy first place steals. I also enjoy the pogo spring being obtainable in Ghost Valley 3 alongside the walls actually disappearing when you hit them, just like the original. Most importantly I love how most of the maps give me room to move around... for the most part. Kinda don't like the random off road bits in Koopa Beach 2 underwater. Sure they are easy to see and dodge but they force very predictable straight lines for traps later in the race. Also, I never liked Choco Island 2 in Mario Kart mainly for the tiny speed bumps, and I still am not a fan of them here. In fact I'd argue with how fast you move in this game having the bumps be so close together is even more annoying to deal with than in say Mario Kart DS.
Overall I'd say this is worth checking out. There are some rough edges but there is some really well made effort in this pack (also it let me play as Luigi so that's a bonus).