Originally Posted by mofomat
Firstly, yes I owned an E46 M3 with SMG II for three years. I'm afraid you are very much mistaken when it comes to how SMG works in manual mode. If you are in 3rd gear for example, in manual mode, and you stomp on the throttle and the software detects you should really be in 2nd, then it will change down for you.
Hmm, are you sure about that. I don't have three years of driving experience in a SMG II M3, but did drive one for about 10 months.
First off, let's define kickdown so there's no confusion. Kickdown in an automatic is when it shifts down to the lowest gear for best acceleration. SMG will only do this while in auto mode. With auto mode in the SMG, you can be driving in 6th gear, step on the gas and get third gear.
While in manual mode, you can be cruising in say 6th gear and fully depress the accelerator and still remain in 6th gear. Also, say you enter a turn in third gear while in manual mode. At the end of the turn, the car will remain in third gear even if it isn't in the best gear to accelerate. It will even allow the car to lug around, low in the RPMs in third gear a bit. While in manual mode, you have to downshift for yourself.
While in manual mode, SMG pretty much only downshifts for you to prevent a stall.
edit: At times, manual/sequential mode will put you in the right gear, but you cannot rely on it to do this. If you want to confidently be in the right gear, you need to downshift yourself, as you would in a traditional manual.