[,,,]
It seems like much of your experience is not as much drawn from the fingering complications as much as from the sound of the various bass systems. The B/C system free basses tend to have long tapered (and linearly arranged) reedblocks which allows to have wind paths tapering along with the pitch. The quint system seems worst in that regard: the easy mechanics may well be bought by a reed plate arrangement that does not allow for an acoustic construction tracking the pitch closely.
So while it seems like a weird criterion judging the various systems (and makes little enough sense on an electronic instrument), the mechanics of the implementations, particularly when the systems are rare enough to not have seen significant evolution, may indeed be something not to be dismissed lightly.
Interestingly, my own instrument (C system in treble and MIII) appears to embrace a "rough tone" on the bass side: as opposed to the treble side, the reeds are mounted on leather gaskets, making for a more piercing tone quality. That allows a wide range of registrations to actually work with tolerable transparency. Indeed, when I want a punchy tone (or avoid fast reregistering), I sometimes revert to LM in the left rather than the right hand (where the L reed is kept in more mellow confinements).
Dak, I have found the 3-row chromatic, either C- or B- has a number of fingering advantages too, even over a PA keyboard in some ways. At least it is true with alternate rows for ergonomic fingering — in all keys.
Closed voiced triads and 7th chords, in all inversions, seem to fall right under the fingers.
Since about 2006, I had been playing a specially made Castsgnari PA, with C-system free bass. The Castagnari has a great sound, on both keyboards. I liked the C-system free bass too.
I had to switch to CBA from PA on the treble side in October 2023 when osteoarthritis finally took away use of my thumbs for legato scales and arpeggios. The experience has made me wish I’d started on CBA in both hands.
A few years ago, a banjo player in a group I had played with knew about a bayan for sale, with free bass. He also played double bass and had played accordion too. The seller was a Russian immigrant. It was made in Tula, had a very nice sound to my ears. Of course it was B-system both hands.
I probably would have stayed with the C-system, but I needed a CBA, and this one was affordable to me at the time
The PA made by Castagnari with the great sound, and a C-system converter free bass. I gave to a musician friend. He been making huge progress.
More on his playing maybe in another post. He brings a wealth of musical knowledge to the table, but accordion is hardly his major instrument. Still he already does more with the instrument than I ever did.
I was able to obtain a Roland Fr4xb too. That was fortunate, since the Tula-made bayan always seemed to need to need repairs.
I eventually sold it (at a slight loss) to a young serious player who wanted to learn to repair accordions. Not sure how she’s doing.
At any rate, in addition to closed voicings, even with just 4 fingers, it’s fairly easy to play 10th, even 12ths on a 3-row chromatic keyboard, especially with alternate rows for fingering.
For what jazz pianists call shell voicings, and 3-note open chords, the 3-row chromatic keyboard is a dream on a CBA keyboard.
Dak might be right that “long tapered (and linearly arranged) reedblocks…allows tapering along with the pitch”. Yet, I did see a video recently of Dallas Vietty playing his PA with a Moschino free bass. Found it to have a far better tone in both treble and bass than the accordion I purchased from Mario M many decades ago. Wonder when Dallas’s instrument was made?
My impression, albeit from limited experience, is that free bass accordions really do sound better when they were made after Lips and Ellegaard worked with the manufacturers to improve the internal acoustics. My guess is that that was around 2000.
So the instrument is still evolving. That happened with pianos too. JS Bach didn’t care for the fortepiano when it was introduced about 1700. He wrote all his keyboard compositions for organ, harpsichord, and clavichord.