I finally got around to doing this job on my '06 DD a while back and I'm glad I did it. Ever since I whacked a bridge approach that was pushed up by frost last winter, the alignment and steering had not been right. I hit it hard on the right and it bent both rims and wrecked one tire.
It must have knocked the subframe over to the left, because my left camber was at -1.1* and my right was at -0.4* which gave me a massive cross camber of 0.7* and it was noticeable in the handling. It also had a tendency to lean right, especially on a heavily crowned road.
I followed the how-to described on the MS forum and it was pretty straight forward except when it came to the actual adjustment. A screw and a nut just didn't cut it. The screw bent under the stress and it hadn't even moved the sub a tenth of a degree. That's when I dragged out the big gun porta-power with a duckbill spreader and got it in between the frame and the sub on the left side and started pumping. Sure enough the gauges started registering the change until I got the difference split and balanced.
Once everything was torqued back down, I checked the cambers again. I was sure I was going to have to go back under and tweak it but to my surprise both wheels were dead even at -0.7*. Not believing how easy this was, I have checked the cambers a few more times since I did the job and they still read -0.7* on both sides.
The job was definitely worth doing and didn't take long at all, maybe an hour at most. I now have all 4 wheels at -0.7* camber (SPCs rear) with the rear toes zeroed in and the fronts at 1/32 out for a total front toe-out of 1/16th, (new LCAs) and it drives/glides beautifully. The steering response is sharp and predictable. This car definitely likes a balanced alignment. I have since put 9,000 miles on my Hankook Ventus S1 Noble2 tires and with this alignment I am confident I will run them beyond the 50,000 mile warranty.
If you are considering shifting the subframe on your 3 or having it done, it certainly is worth it.