This IS an instrument "Specially made for Jazz, Pop, Salsa or Big Band music" to quote the product description, and has a very small bore by modern standards.
I use it in a small group setting where it has a nice warm "core" sound at a lower volume and speaks very clearly when played loudly.
Playing high and loud it projects well and has a nice controlled tone when played in the lower register. I haven't felt the need to change to a bigger mouthpiece yet.
It feels like a very solid instrument, and a little heavier than I expected, the (very smooth) nickel slide is a little heavy compared with similar instruments from the USA. I don't have a problem with this and it may be the reason for it's solid sound.
The build quality is exemplary, there's not a trace of solder around any of the joints, and having played it a lot since August 2012 there's no sign of lacquer wear at all, not even on the neck pipe.
I bought this instrument knowing nothing about Kühnl & Hoyer, but after hearing a few users on YouTube I took a gamble and bought one.
It would be good if the removable leadpipe option was standard and with a greater choice, 3 rather than the current 2, one of which is sterling silver, which is very expensive..
To sum up, it's more "vintage Bach" than "modern King", and made for a specific purpose which it does very well.
