WTF are the M Multifunction seats on the F10 M5?

[seech]

No one, not even 'Internet', can succinctly describe the difference between the standard sports seats and the M Multifunction seats. I gather they aren't active side bolsters like the E60 M5, but is it just the addition of some lumbar adjustment? Put a deposit down on one yesterday with a lovely spec including the above.

It was standard on my C63, seems a bit odd it's an option on the M5 as my E90 M3 and even our old 1 Series in 2006 had inflatable side bolsters.

[seech]

Thanks V5. Some BMW literature I read says that you need them if you want the seat vent or oscillating base, but doesn't say what they do over standard

[seech]

Thanks.

Knew they were a must have but surprised at the lack of info out there, especially from BMW!