That's the ecoboost in silver it appears. The wheels suggest performance pack and as it pulls away you can see pony without tri bar logo. So the mag has the video mislabeled. It's not a v6
Current V6 Performance pack with 3.31 gears does 0-60 in 5.8. I'd expect with the 3.15 gears it might do it in a little more and with the 3.55 gears it'll do it in a little less.
So, I think mid 5's (5.3 to 5.5ish) for the ecoboost with performance pack is realistic. It'll have a much flatter...
Problem is the tail light surrounds on the 2015 are not aluminum colored like they are on the late 60s. On this one you'd have tails with black surrounds and then a random aluminum plate in the middle...
According to the leaked and seemingly authentic weights - the 2015 V6 is only 20ish pounds heavier than the 2014. So, I agree - the weight should make little difference.