Well this is coming from a corporate pilot but the Citation 650 has EDM (Emergency Descent Mode). Above FL 34,850, if the cabin altitude went over a certain level (I think 13,500) the aircraft would automatically enter a 45 degree descending bank 90 degree turn accelerate to Mmo/Vmo and automatically level off at 14,500. Pretty cool stuff, of course if you weren't conscious enough to add power at 14,500, things got ugly pretty quick. Of course if you weren't concious when you got down there, you probably didn't care anyway. All you HAD to do was put your mask on and pull power. If you could get the boards out it was gravy.
All that being said, I would still rather hand fly the airplane.