I have a is250awd with the 6 speed sequential and use it all of the time. I have only ever used the automatic setting once when in heavy traffic. I also keep the ECT setting on pwrECT(im not shure if it makes a big difference in sequential mode but it seems to shift a bit quiker. As for control, the transmission seems to let u do what u want. You can shift down just about whenever u want, but if u really make a mistake, (for example- 3rd gear 500 rpm to 1st) the car will beep. But like i said the car rairly does this and ive one experienced it once when i accidently hit the paddle, and i tend to shift down quite aggressively too. As for up shifting it lets you do whatever u want. It will allow you to redline without shifting etc. The only drawback however is if u are in a high gear at low rpm and step on it the car will shift down according to what gear gives u more power. But if ur driving aggressively, cahnces are ull keep the car at high enough rpms that the car will not do this.