Cerb: First off, what is it that you're saying isn't entirely true? I'm not quite sure what you're referring to. I went into the Control Panel options and didn't see anything that would allow me to mess with the sensitivity. I went to the website, but the only additional software they have is gamepad mapping controls.
The XBox360 controller, eh...? I've heard a lot of good about it; can't say that I've used it (obviously), and I'm sure the endless questioning about where my XBox360 would get tiring, but I think I could deal if it was worth it.
Does it have four shoulder buttons, though? I'm really specific about that, if nothing else.