I loved it at times but I hated it at times. The was really cool to have 'unlockable' karts, so every character could use every character's karts. It had great character selection (10x better than Mario Kart 8's character selection in my opinion). It was challenging when I was a kid, so I had to give it to my older sister to beat the Mirror Cups XD. When I got older, I went back to Mario Kart DS from playing a bunch of Mario Kart 7 (3,000 VR if I remember correctly). The drifting was all conky, but I got used to it. I also learned how to 'snake'. Basically if you drift really fast, then let go of drift, then drift really fast again, you can go really fast. If you snake at the beginning of a course, and you held your snake, it would act like you have an infinite mushroom boost. You could go over grass without being slow down. The only bad thing about this is that it destroyed your thumb. Halfway through the course, your palms would be sweaty and you thumb would be burning. The course ends and your thumb is sore for like ten minutes.
Well, that's my story on Mart Kart DS, second best Mario Kart game in my opinion.