Hello.
Well, I did try several "good" concertinas:
Geuns-Wakker's Anglo, Morse Ceili, Wheatstone English with metal raised ends and 8 sides and another one, with brass reeds, made in 1850.
Admit, duets were of the cheap sort.
On duets: I have decided against them because I liked push-pull Anglo better. So after trying very nice brass reeded 20 button Lachenal I went to obtain finer instruments. After trying the good ones - moved back to accordion.
I agree, a good player can play from wisper to thunder, but by some misterious reason it takes more effort, than on accordion. The cheap Delicia reeds in low end Weltmeister do better dynamics wise, than expencive Geuns-Wakker. May have to do something with the volume of bellows, I don't know.
On learning the system.
Learning is life. Complaining to difficulty of learining is like complaining to difficulty of living. Sure it's no picnick. A mistake many make is thinking they can learn it and THEN start playing. There are brutal concequences for such a mindset. We parted with my accordion teacher because he was of this opinion: tolerate the grunts of exercises to learn the instrument, and after a few years you'll be playing. What a terrible pit of self-worthlessness I had made of myself to cave in to such bizarre concept.
On irregularity.
I was learning two systems: Button diatonic accordion/Anglo and B-system Chromatic accordion. B system is 100% regular and chromatic. All the notes are where they "suppused" to be. Playing chromatic scales is easy. But playing "easy" folk tunes was a hardship, I wasn't prepared for. Especially compared to easiness of diatonic instrument.
Piano keyboard is the most intuitive and easy to understand. Is it easy to play?
There is a reason behind irregularity of bandonion. It's "playability".
I think if "illogic" keyboard drives you nuts, you may not be learning "it" correctly.
It's like learning a language: speak! Make mistakes and go through. It will come together regarless of how much grammar you know.
On talent.
No, I'm not all that talented. Just happened to discover a good method of getting introduced to varios keybaords.
Though it is very easy to learn simple tune on any keyboard system in a few days (decently), by no means it guarantees further success, as while you are getting familiar with buttons, you start hitting the necessity of expressiveness. And that's where your talent or lack of it will start playing the major role.
Discovered it the hard way. After all, there is a reason of why most of us have day jobs.