Void Eclipse: I am playing on the very hard difficulty, aim assist is off.
I am not that MLG pro, but there are few moments. As soon as you get good weapons for headshots, game becomes easy. And if these weapons are tech ones, you can land headshots through walls, facing no danger at all.

Ping your foes, tag them, kill them through walls with headshots, kill them faster if they stick their heads out.
On the other way, how could you fix this, by nerfing everything that works and making enemies into bullet sponges? That will ruin all the fun.

Maybe the solution will be in making enemy AI more aggressive, i.e. charging into player as fast as possible? That will make sniping much more difficult.

Another option - make enemies to move faster, and in less linear way, so you will have harder time to aim at their heads - because now they move steadily, or stay behind covers on the same position. Without introducing "unfair" difficulty it will rise skill requirement for combat snipers.

The last option is to make enemies throw grenades more often. So a sniper won't be able to stay in the same position for long.

Ixixly: Void Eclipse, have you left the starting area yet? Try heading outside of Little China district where you start and it gets a LOT harder out there. Was getting along really well in Little China like you stated usually using a good Revolver but decided to head over to Downtown and Corpo Plaza as a level 14 and got my ass handed to me! I grabbed one of their weapons on a sneak mission and can't even equip it till I hit level 30 which says a bit and the weapons I had, whilst decent in Little China barely made a mark on them in other areas.

Void Eclipse: . As soon as you get good weapons for headshots, game becomes easy.