I have one that sits in the corner of the garage now ... I think I paid $350 for it ... through this site I learned you can't really "buy" a game off the shelf. So I took the Edel challenge ... I went and got fitted ... the BEST singe club decision I ever made.
I will add ... my Edel putter combined with an aimpoint class, has me putting like a low handicapper. Could not be happier.
Even with a good swing golf is hard.
The main thing you don't seem to be understanding from us is that the setup is only a small percentage of a good swing. You are now finding your ideal setup and it works a lot better than other setups you've tried, and that's great. Many of us have been through this phase.
However, once you have this and eventually develop good full swing mechanics, golf is still hard. You still make misses, only as you get better, the misses are not as penal but they still cost strokes over the course of a round.
The understanding you seem to have is about what I expect from a 15 handicap, and that's good but there is a lot more for you to learn.