To IRIS or not?

I am new to the forums and am finalizing my MP4-12C order for an April delivery. My concerns / questions revolve around the IRIS system, as it is no longer a "required option". In the States, this is a 6,850.00 adder. The way I understand it :

Standard sound system :
Meridian sourced
4 speakers

IRIS :
Meridian sourced
7 speakers
Voice activation
WLAN connectivity
NAV


I have read comments from McLaren that IRIS will do things never before seen in the industry. Any clues?
Does anyone have a working IRIS to report on ?
Sound quality difference between the two ?
A power difference / subwoofer ?

If it’s going to provide satellite radio, a back up camera, over-the-air software updates for the car, in car telemetry, in car dyno, or race track playback, I would find it worth the adder. 7K for nav and 3 more speakers is not something I want to blindly sign up for.

Thanks !!

Bill