Interesting....when I bought some Adox Silvermax two years ago it came in a metal, non-reusable cassette.
I've had Foma 100 and 200 in metal DX coded cassettes, and 400 in metal non-DX cassettes. These new reusable cassettes are a new product for Foma and if I didn't already have 30 or so good plastic cassettes (some with DX codes) I'd definitely be looking at those.
For the record, the 10 exposure "Power Geek" C41 film available in the UK at Poundland stores comes in plastic, non-DX coded reusable cassettes.
*most* cameras either don't use DX codes in the first place or can be manually set. However....as much as I love my Praktica BX20S cameras, they only have the ability to set 25, 50, 100, 200, 400 without DX codes. This is achieved by the compensation dial....so if I were to load DX coded cassettes at 400, I could instead select 100, 200, 400, 800, 1600 which is a decent spread of speeds. In practise I bought adhesive DX coding strips from Firstcall Photographic and have coded about half of my cassettes at 200 or 400. Some I bought already coded at various speeds.