Also, in regards to neck widths.
Like Ian said, it’s actually a bit hard to play precisely on some of the very narrow hosozao shamisen at first. I started on a loaner from my teacher that was about 2.5 centimeters wide; moving up and down was extremely fast, but hitting the right string was rough.
When I moved up to a 2.6 (the upper limit of what’s considered a hosozao) I started having a much better time with things. I’m sure that was partly due to my overall skill level increasing, but that tenth of a centimeter felt gigantic.
I mostly play on a 2.8 cm chuuzao and a 3.0 cm futozao these days. Both feel good, but both took a little while to get accustomed to.
Also, having played on the 3.3cm futozaos before, I have no idea how people use those. They feel mammoth