It seems strange to me that the D-link is promoted in the Apple community (by Apple) and that to make it work you have to upgrade the firmware
Apple got strange with Steve. I get used to that. Yes, it is a terrible situation but I do not create them. The D-Link works, just headset needs an update. The Bluetooth mice and keyboards need updates as well.
Why does D-link not sell a DBT 120A
Because they would have to go through a costy Bluetooth qualification again and because of the HID proxy of the new firmware, compatibility to Windows is questionable.
you can find a lot of people reporting that the D-link is dead after the firmware upgrade.
Show me one which was not solved in the course of retrying.
That's lottery as well.
No.
A firmware update is no lottery. You follow the rules, let it work overnight and it will work.
I do not get the push of the D-link adapter
Because there is no other adapter which is sold worldwide and prooven to work. You do not even have a model number or revision for us. Just a brand name which is useless. For example the D-Link DBT-122 works not for headsets on a Mac. The older DBT-120 revisions of the D-Link DBT-120 either. Apple users expected to buy something and work with it. Yes, in this case you need a special step which is called firmware update but at least you do not have to rush out and buy a dozen of Bluetooth revisions.
Fine it works for you but I can't even find the brand here despite a model or revision number.
Remember we are talking about headsets everything else works so lala with other adapters. But in my personal experience I have to recommend the D-Link DBT-120 + fimrware update because I know this is the best tested device by Apple and **** there are new bugs everywhere with other devices.