Hard rubber is a wonderful material for a clarinet. This material has a lovely dark sound, is totally impervious to changes in temperature and will sustain itself without the terrible binding that those who play in ensembles daily experience. I have seen so many students with barrels of wood that cannot be gotten off without using a reamer.And the cracking and the helpless feeling of seeing an expensive clarinet with a crack down the side of the top joint. This does not happen to an instrument of hard rubber.
The best person for advice on hard rubber and its use for manufacture of clarinets is Tom Ridenour. He has a website easily found. Read his essay “The Myth of Grenadilla”. He is a master clarinet craftsman.
The history of the Arioso clarinet is interesting and if considering the purchase of an Arioso, write directly to Tom Ridenour. His website is easily found.
The old arioso company is moving in a direction more for students, early students at that, and Ridenour has no further releationship with the old company, rather he is producing a new and much better Arioso himself and offering an interesting package of extended care as well. I suggest that you get in touch with him directly for all the particulars. Rest assured the highest standards of professionalsm will be adhered to any clarinet which Mr Ridenour produces.
Stay well and play well