Neumann use ATC I think. PMC use two versions the Volt clone of the ATC super mid and a vifa/scanspeak 3inch fabric dome which has been used in a few other model of speaker.
The problem with this type mid is that it is hard to build (double spider) , tight tolerances and large magnet (bigger than most woofers) and so it ends up being costly.
Proac used ATC for a while not sure if they also used the Volt version.
Genesis had a 3.75 inch dome mid in the past. Also Energy Veritas has a 2 inch metal dome.
I think B&O had a model of speaker with the scanspeak/vifa 3 inch fabric dome.
The scanspeak/vifa version has a very small motor.
I think only ATC and the Volt clone are double spider which is a key aspect of the design as a 3 inch dome will undoubtedly suffer from rocking modes unless a dual spider is used.