From WiiRincontrol:

Yes, there is a difference in control between 50cc and 150cc, but that is the nature of driving. Steering your car at 50 mph is much easier than doing so at 150 mph. You must react quicker, you must be more fine with your actions. It is the same with Mario Kart. I call laziness on all who claim that this game’s motion controls are broken above 50cc. Video games are about mastering the controls in order to win. Mario Kart Wii has above average controls. Master them rather than complaining that motion control was added to the game, or use a GameCube controller. It’s that simple.

Related posts:

1. GameSpot: Mario Kart Review & Video Review
2. IGN UK: Mario Kart Wii Review
3. GameSpy: Mario Kart Wii Preview
4. Mario Kart Wii Review - "one of the top three games on the system"
5. Wired Review: Mario Kart Wii Skids Way Off The Road