Well, definitely everyone has their own opinion on each Mario Kart game. And honestly I thought that Mario Kart 7 was by far the weakest Mario Kart game yet. I personally didn't care much for it, and not because of the kart customization, but the game play was absolutley terrible. Sure the courses were all new and cool, but the Rubberbaanding on the the AI was ridiculous. Even when you think you are in a pretty good lead in 1st, as soon as you get hit by a Blue Shell, you'll find yourself all the way back in atleast 6th or 7th place and won't be able to catch back up. The item spamming the AI uses doesn't help either, since you really can't avoid it. Of course I'm saying this with you racing on 150cc. 50cc is a joke and 100cc isn't that bad. I haven't played it on Mirror Mode yet, and I probably won't.
This game is either loved or hated. Even though I tried to play it for as long as I could, you'll find yourself getting bored really easy especially when and if you start farming for coins to get your next kart customization. However, though the online play is fairly good and that is by far the best point in this game. This game is nothing like the DS or Wii version as they were, in my opinion, MUCH better! But hey I'm not going to discourage you from buying it, because it is worth it in the end. It's just really annoying and frustrating.