I used Harmony for years. I had a Harmony rocket, that I paid 150 for, sold it to a guy in the Navy for 300, went right out and got an acoustic Harmony, had that for a long time. The latter was a perfect, take to the beach, kind of thing.
I've notice an improvement with Brass pins, but mainly the higher strings.
I would think that if there wasn't someone better then me, I'd be worried then! You reach the top, and then, what? The thing I love about the guitar is finding, learning something new, or different about it! ( Try Celtic tuning )
Can I refer to an old Bob Dylan liner note here?
Two fellows sit down at a chess board. The first says, " I've played chess for years, thousands of games, never lost once!' The other fellow says 'I played for years too, and very many games, but I've never won one yet." First guy gets a grim look and says, " Now, I gotta win."
Take an empty sheet of paper, start to write, and keep going until the paper is full. It won't matter if you have a theme in mind or not, it won't matter if you spell any of it right. Just keep going. Don't erase anything, just keep going. Once you've filled it up, walk away from it. Put it in a drawer and walk away, and if you feel you need to add something else, then just take another sheet and fill that one out too. Try not to go to fast, and don't slow down either. Just write, anything, any combination of words you want, and, at some points, words you can claim you don't know at all. ( You'll know those, when they come.)
Now walk away, paper in drawer, come back, ?tomorrow, a week? ?/? untill glass becomes water?
Once back, put your hand over the middle of that page, draw a circle around your hand, read what's inside the hand. That's what you were trying to say, now you get to understand yourself.
I think an example would benefit you more. I'd say take Carol Kings piece, 'Up on the Roof', which is basically a 3 chord song, then look at how James taylor has done it. He's weaved some interesting twists though it all. To be fair, it just maybe be that I haven't tripped across a Carol King Tab that really was broken down anyway. At any rate, it's still a good study.