i have a MBP and i have never heard of this sudden motion sensor?? haha

but ive never had a problem playing in clubs or at festis! my laptop has been super solid for 2 years.

In the older G4 MacBooks the sensor was a lot more sensitive than the current ones, something on the order of 5X.

Hmm. In theory the drive heads would not park just from vibration, since the sensor has to detect sudden movement on all three axis. That would have to be a ton of vibration, enough to threaten turntables and some CDJs as well. When I was using the Odyssey L-Stand I used to be able to see my MacBook vibrate a great deal, although it never caused a problem. Now I use a Stanton Uberstand and the stand absorbs nearly all of the vibration.

I think for piece of mind you might want to consider an vibration dampening pad, you should be able find them wherever studio monitors are sold. Actually, a more readily available and likely cheaper option would be to go to a sewing machine or woodworking retailer, they sell vibration dampeners for small machines. If it will stop the vibration of a motor running at hundreds of RPMs, it should absorb the bass nicely as well. Any porous rubber would do the trick, preferably neoprene as the air bubbles in the materials are larger than other types of rubber sheeting.

i've never heard of this either - but I played a gig on the biggest system I've ever seen last summer with my macbook and had no problem whatsoever - and we had two gigantic 3-way JBL cabs right in our face for monitors and they were providing plenty of vibration.