No, it doesn't have a mechanical limited slip. The traction control tries to pretend like it has a limited slip differential by braking the spinning wheel, thereby transferring some torque to the other wheel on that axle, but its only so effective (As are mechanical limited slips)..

Now the (xdrive) Center differential is electronically controller and can be 'locked' if necessary by the computer to provide 50:50 transfer of power front to rear..

Therefore, my 25 year old E30 has a far superior AWD setup with the viscous center and viscous rear diffs, still an open front for turning reasons. Same diff technology as the //M cars (where do you think they learned it).
Yes, there are limiting factors on the performance of the locking diff's though, the Tires' traction, and ground clearance. Blizzaks take care of the first one, plowed roads take care of the second :) Have never been in want of traction control and I love trying to find hills that I can't make it up (0 so far). Also, no traction control means I don't have to worry about ever burning up the brakes like I do on the X5 (since it can't be fully turned off).

It wasn't snow. The snow was inside the parking spot. The ice that I has to go over from the street was really high. I actually took a pic, but you can't tell what is going on as everything is white, and I couldn't get back any further to take a better pic. So fail there.

Yea I get how the DCS and traction works, but the strange thing is that instead of my usual rock it back, and get some momentum, I just floored it. It dug through the snow I was in, and over that ICE wall. It was freaky coming off the ice. But really surprising the X just took it like a champ.

I looked at my wife with a surprised look, and she was looking back with a shocked expression. This just after her bitching at me that we will never get out of that spot. And her moaning before, that I will never get in that spot. HA.

Again, my main shock is that I floored it, and it came out without a hick-up at all, slowly. While when I was going back and forth, I would slip straight against that ice.

Oh, I didn't get high centered because I came in, and out sideways.

FYI, you don't need to floor it to get that to happen in the future. the ASC+T portion of your DSC will limit your engine power to what the tires are able to apply. So, 1/4 throttle probably would have done the same thing. You just have to be patient and give the Xdrive time to respond to what the DSC is asking for...now if you turned DSC off before you floored it, you would have gotten a more 'rapid' descent off your ice wall ;) I'm sure your wife wouldn't have enjoyed that as much as you.