Kyros Valchion
Wangan's got a different system that's easier to get into than D. It isn't as technique heavy (D has eraser, ALEX@, and TST).
Good point, another important factor is that Wangan's physics are static. They stay the same.
In initial D the car handles different on every course, and in some cases, specifically on certain corners in Iroha, the car violently understeers more than in any part of the game.
In Wangan, if your car slides funny or such, you go "Aw damn, I need more practice."
In Initial D, if your car suddenly gains grip and you rub your nose into the inside wall and now you have a magical speed penalty, you're left saying "That didn't even make any ******** sense!... Have the sega rosso guys even ever driven a car?!"
In closing, Wolfe brought up a good point, Wangan's system is a lot more fair, and leaves much of the race up to skill. Two drivers with 700/B cars, the win is to the better driver. In Initial D its all about who has the most blue stars (LOTS completion) and tuning points. Wich might I add goes against the very ideals that are glorified by the anime/manga.