What is missing from the 0-60 in .5 seconds is time to distance & acceleration rate.
Cars at this level a .5 second spread is watching the other cars license plate get smaller. The plate will continue to get smaller as the rate of acceleration continues to favor the quicker car.
Beauty of a car or the relevance of a .5 spread is in the eye of the beholder. .5 tends to be a big deal to people who compete & not much to spec racers.
BTW YouTubes of tachs & speedo's are pretty meaning less as a measuring device. You need at least one of these to get good numbers.
There is about a .5 spread to 60 in the 328 before & after tuning. Both these car had equal 60ft times but by 60 the faster car was in front & extending its lead. By that time both cars were near their maximum acceleration rate with the faster car only gaining .1 over the slower car but still finishing well infront.
No a big deal to some but the end result is in a two car run one is a looser. By the end of the run the modified car will be moving at 172 feet per second as it finishes .6 ahead of the stock car.
Faster cars like the M3/4 & M235 will only increase this spread due to higher terminal speeds.
On a road course like VIR the stock M4 is about 7 seconds a lap quicker than the M235 an eternity in road racing.
So in my case the winner of the beauty contest is the M3/4. The winner of performance per dollar spent is the M235. But since the OP is bucks up & can buy an M3/4 if he chooses that's not relevant.