Ok, here's the deal: I started typing (QWERTZ) about 15 years ago. At first rather hunting and pecking, I developed my own technique of hitting the keys, while not really looking at them. After more than a decade of random key-hitting, I could type blindly on QWERTY at about 70 wpm.
Any attempt to learn touch-typing with QWERTY seemed to limit me, so I never really gave it a try. Recently, I started touch-typing with Dvorak. A made progress quite quick, and after a few weeks reached 50 wpm. Still, after 3 months of training every day, I can't quite surpass the limit of ~55 wpm. Typical touch-typing feels limiting to me right now, while using my own system works quite different: My hands rather float freely above the keyboard, and I have no real rules as which finger has to hit which key. I usually thought I'd "improvise" while typing, but dealing with typing and layouts I believe I merely learned how to type certain words most efficiently. In fact, I think that's what most people do, who don't really care about their typing habits, but nevertheless do a lot of typing regulary, thus improving their typing speed on their own way.
Do you think that all these years of "wrong" typing have slowed down my progress of learning correct touch-typing, or could it really be that touch-typing limits me physically, and I should rather stick to my own ways?

tl;dr: I think my own style works better than touch-typing