the thing is, if you really need a low G on the
pull, it;s on the left hand anyway.
that low A is more useful than a 3rd low G
[counting the #2 push]
i use it all the time but
a. i play zydeco [though no other
players seem to have this at all -
i just like being able to play things
in the low octave as a variation - and
having the low A is indispensable for that]
b. i try to use it, because i like it, which
is why i have it
There are different types of nine-button accordions. What most people see these days is one that is shorter than a ten-button accordion and a little wider. The other type is mostly associated with accordion builder, John Hebert. Mr. Hebert built a regular sized accordion, but just left off the top button. One of the first accordions I learned to play on was an "Hebert." There aren't many around, but I think that Jamie Berzas still plays one regularly.
As for volume and such, I think the same factors that create noticeable differences in accordions from the same builder also stand true here. I'm sure there are some scientific equations to calculate the difference in air volume and pressure created by the different bellows sizes, but personally, I have not noticed any big difference.