Dick, as so often appears to happen, you seem to be finding an argument where there is none.

No one has disputed that accordion reeds are different. I wouldn't even try to argue too hard that they are not inferior - they are certainly easier and cheaper to make, which is of course the point. The question is whether they are fit for purpose. As someone who plays melodeon as well as anglo (as does Brian Peters, of course) I can attest that I have had no more problems with durability or tuning from accordion reeds than I have with concertinas.

I'm sorry if I misunderstood your point, but for most of this thread your objection to hybrids has been that you believe they sound like accordions. I now understand it is lack of volume which you find the problem. I don't agree with you about volume - it depends on the reeds. My Castagnari Mignon single-reeded melodeon is a real screamer which is easily comparable in volume to my Crabb and Dipper concertinas, and louder than my Lachenal.

As for hybrids sounding like an accordion - I suspect I couldn't tell the difference between a single note played on an accordion and on a hybrid, but in practice they sound completely different because they are played differently. A hybrid sounds different from a traditional concertina, but it still sounds more like a concertina than an accordion. Individual accordions of course all sound different, as do individual concertinas.

Using accordion reeds makes 30-key instruments just about affordable, when the price of traditionally-made instruments has gone through the roof. The hybrids I've come across have all been of very high build quality, and the only compromise is in the reeds. Of course this affects the sound, and if you don't like the sound then there's no more to be said. For very many players it is a compromise they are prepared to make in order to have an affordable instrument which meets their requirements.

That last point is crucial. I have never disagreed that if you don't need the extra buttons then a traditionally-made 26-key might be the better choice. I'm glad you have now recognised the corollary point, which is that if you do need the extra buttons then a hybrid is really the only affordable option.