Well, it may not be the best sniper rifle regarding critical damage but it suited my character perfectly: A sniper with thought control. The +20% to precision is golden because that allowed me to have a perception of only 10 and still have 95% hit chance on any range (well, not in close combat lol). Up to the point where I finally found Black Arrow (thanks to epeli) I used a sniper rifle with a normal scope and a bipod for the +20% hit chance. I would even put less points into perception but I used snipe very often, which needs 10 perception. You can combine Black Arrow with Neurovisual Disruption for cool results I guess, although I couldn't find the psi-trainer for it. With all the Crowd Control like Fear, Subversion etc. I could often go into stealth in the middle of combat and use snipe the other round to kill almost anything with one hit. I also decided to completely leave out critical damage so it didn't matter that black arrow has low critical stats which also allowed me to have so much more feat points.