Honestly, I feel like this vehicle's super overhated, and I personally have fun using it. Even if it has the worst drift stat, I don't struggle taking turns too much as long as I go at the right angle at the right time, and it can feel really satisfying when you successfully utilize the outside drift mechanics to pull off some tricky movements. It has good handling, too, so if you don't think that you'll make a turn with drift, you can cancel the Mini-Turbo by releasing A and let handling do the rest. And even for it's awful drift, all of its other stats range from okay to great, notably its off-road as it's the best of the large vehicles.

I was trying to figure out the 'RS' and 'KC/BK' variations, but now I know the 'RS' handlebars are closer together and the 'KC/BK' handlebars are further apart.

Rocket Harley Davidson.

This is considered by many to be the worst vehicle in the entire game. While it isn't necessarily slow, it has the worst drift in the game. Much like the Wario Bike, the Phantom is an outside drifting bike with a terrible drift stat, and that is probably the worst combination besides being slow and light.