Self tensioning seat belts - any information about them?

My wife absolutely loves the self tensioning front belts on our 7er - the way it tenses then slightly releases. I don't think this feature has filtered down to other cars yet. I expect this feature is for safety, where it estimates how much to draw slack in, rather than comfort, though to her it feels that way.

I don't recall any marketing or release info about this feature. Does anyone have any insight or links to information about this feature?

I recall my E65 had it. One of the only features I don't like

My 2011 Mercedes GL550 also had them. You could turn it off, if you wanted to. Under Convenience in the settings, you could enable or disable. I always thought it was odd, that you could choose this!

My e92 had this feature as well and I'm also not a big fan of this feature.

The feature is fine, but the way in which it is programmed is not. When I start the engine, buckle the belt and reverse, the delayed tensioning interferes with looking back, over my shoulder. Very annoying.

Most of my passengers are surprised by it, but seem to think it's pretty cool. If it saves my neck in an accident I'm a fan as well, but I also agree with DBS about it interfering when attempting to back up the vehicle. Maybe they should delay the auto-adjust until you pass a certain threshold such as 20mph.

Agreed, AdamG; 20 mph would work. Also forgot / realized again this morning that it interferes with wearing a tie and wanting to flap it over the seat belt so it doesn't get crushed / damaged; a delay would solve this as well!

I generally let my engine warm up a little, usually until the idle drops to around 800rpm (about 10-15 seconds), so the tugging action doesn't affect my reversing.