It's a bit old school and lacks some features of newer slicers, but I still use Simplify3D quite a bit. If you're printing stuff that is largely just "a box with holes" (I print a lot of planters for my indoor and outdoor garden), its great. I only really print functional parts like that, so its hard for me to think of any models where Orca produces better GCode for my jobs. That being said, I have Orca configured just in case Simplify3D ever goes away.