No way! In order to use criticals (for aimed shots anyway..) you have to specialize your entire build for it, and still BG goons take you out plenty of times.
Yes way... I have 10 end and stonewall and I get knocked out and killed by every single crippler I ever face. it's either: Instakill or Knockout (Another form of Insta kill

). Not once except one time i found one of these laser pistol guys in bluesuit and I happened to stumble across him at 1hex already did I ever killed a sniper. I'm not fucking joking. It only takes 2 shots and I get killed. where as to kill a sniper bg has to get up at 1hex or be a critical damage burster that does huge damage regularly at any distance but even then he has to give up some stats like Endurance to make such a build.
Unless there's more than one bg a lone bg vs a sniper in 75% or more (99% in my case) BG obviously loses. Besides that, a sniper can keep a big gunner from being able to even use his weapon even if he isn't knocked out by breaking his arms, and he can break his legs so he can't run away. There is simply too many advantages snipers and cripplers have against big gunners.