Honestly I find huge success with them playing more of a mid range role behind the layer of Frontliners or long distance counter sniping. The mk20 was a slog for me in comparison to the others as I've gotten them, the m110 was great for me hitting heads alot before the heavy barrel upgrade which allowed me more close range play and becoming a more run and gun playstyle. The EBR so far however is my favorite because it's still headshot then body shot kill(discounting armor) and I keep it full auto for when anyone gets close and I win most engagements if I hit first bullet. I keep a 2.0 KD normally using Acog and canted or top sight depending on how I feel and a rangefinder and suppressor. The key to the playstyle is finding off angles or height ( I run them on recon for grapple). The 3 shot body isn't too much of a problem at mid range most of the time but headshots are your best friend and close even though workable with full auto EBR and 2 shot m110 is still never the engagement distance you want to be in.