I was taught how to use Gibbs in machine shop school,because I suggested that the new instructor try it,because he couldn't do ANYTHING on a Haas lathe or mill even using it's interface,because he had always used Mazak or Trac machines in his CNC experience on the jobs he worked before he started teaching.
When I left,every part he had made up till that point was made using Gibbs generated code.
Because I had been reading up on general g-code practices,I was very comfortable manually g-coding a straight line,even if I told it to take one pass down the middle,then go another .015 to either side,even taking passes at incremental depths.
Under my old instructor that left before I graduated,I wouldn't have even got to RUN a Haas mill or lathe until I showed him I could manually write such a simple program. Now,using circular or helical interpolation (round circles with an end mill for boring and thread milling)as well as ramping to depth instead of plunging was never shown to me,but learned linear interpolation on my own while at the mill.
Now,using Gibbs was pretty easy as far as drawing the part you want to make,once you got used to how Gibbs works as far as it's program,but no different than learning to use AutoCAD or even Photoshop.
Gibbs is highly effective,but not cheap. Even the copy the school bought was 500 bucks with just "posts" for one lathe and one mill. If you had a capable machine for doing things like 4th axis inlays,it could probably still cost a few thou,because someone at Gibbs or the guy that shows up from Haas will have to write a post specifically for your machine.
Gibbs will also not run right or even at all in some cases on anything but an Nvidia video card.
Where a program like this comes in handy is where the part rendering and simulation helps you work out kinks in the program before you waste a bunch of nice wood. Tommy D.