It feels the best rolls of the best weapons are still world loot drops. Initially I didn't think I'd want to shape either since I hate this system with a passion, but there are a few decent weapons with good rolls. I just check light gg first to see what perks are available. As for leveling the weapon yes it's stupid and grindy but a few Shuro Chi add runs or Grasp add kills in the front doesn't take too long. Shuro Chi adds are close to 1:1 about 80 kills usually gives 65% level.