I know a guy who took a 7.62 Ak round to his body armour in Afghanistan and he said it felt like getting hit with a sledge hammer and it broke his ribs and he was made combat ineffective and got flown out to Bastion for a check up and that was only a 7.62 standard round from a Taliban's gun, most modern armies use an AP type round and these were designed to penetrate armour. A .50 will penetrate just about all the body armour out there and if you get lucky and it deflects away you will be lucky yo only have a huge bruise, be combat ineffective, and possible broken ribs IF YOU'RE LUCKY, snipers use ammo that will penetrate body armour at extreme ranges (if anyone shows the medic survive that sniper shot next to a Humvee, it was a dragunov firing in 7.62×54mmR not .408 in ARMA 3 or .338 lapua (british) or .50).Dragonskin is good but it does have some well documented weak points. plates in the current armour have been known to shatter when stopping multiple rounds in quick succession. also the body armour has many gaps eg in the side and groin etc. Helmets are designed to protect from blast and shrapnel and lower calibre weapons but they are trying to make them stop up to 7.62 by studying the miracle shots that deflect of the helmet. I think that this would be good if they get all the weaknesses and variables in and just have a few dedicated servers running it as a mod (paid for by Bohemia) it would be good, but to balance it I think that an incredibly advanced wounding/bleeding/bone breaking/internal wounds system would need to be in place so that medevac's to base and onto an operating table would be required to survive more serious wounds. Also putting in stretchers and a leaning on others system to make a really realistic server.
Also lots of people are saying about more advanced armour in the future but remember that as defence gets better so does offense & vice-versa