The Eclipse type jig certainly is the one to own when you begin in sharpening.
I did'nt use it when I was a beginner, but now I can't do without it. I learned to sharpen free hand using Mike Dunbar's technique (sand papers of several grits glued up onto a flat surface) That technique is simple, efficient, fast, clean and inexpensive and it is a good method to start with. But it is evern more efficient with jigs.
I can see two reasons to use a jig:
1- You can achieve a perfect bevel and edge every time,, you never miss a sharpening, whatever abrasive you may use (sand paper,