Seems like Madonna was more of an annoyance. I guess they just took the personality and transferred it to Amy or something. The concept art seems to show Sonic not very happy about her.The only reason I wouldn't want a human Sonic character would be if it turned into a Princess Peach type ordeal, with Sonic having to rescue the same person every game.
Anyway. I've tested the Simon Wai prototype... I totally see why Tails gets some hate. His AI is the dumbest thing I've ever seen. And he loses all your rings when he gets hit, even off screen. And you can't even help it. Thank Glob that never happened.