Magura is still making them. But...... from one angle they are great because they really can stop you. And then, they are so powerful that you really can't use them for serious riding because you risk broken fork and injury. Not on the first ride but.....And then for some casual riding you can use decent v-brake, The only advantage is that because of their stopping power they work much better in wet conditions than v-brake.
And they were also wearing out rims much faster than v-brake.