Simple difference, you can’t take the ACR to work without seeming ridiculous, while other high end exotics or even a stock viper will merely make you a deuche but won’t look out of place.
On the other point these times really don’t matter for anything else other than a marketing gimmick fan boy time battles. The cars are adjusted from being showroom floor, there is no sanctioning body making sure the cars are legit and does any owner actually give a shit that their car just went a second or two faster around the 'ring? Few if any will barely see any track time or much less the ring and what a professional driver will set on a 10 mile course has absolutely nothing to do with the fact that an owner of an ACR will arguably be quicker around most tracks in a stock E46 M3 rather then spinning out everywhere in the ACR.
Leave the 'ring times to race cars.
I give more value to the time set by the ACR-X than just an ACR.