You are correct. To date, I believe Technics has the most 'User Friendly' OS which is definately missed.
As Arrangers become more and more complex, so too do their OS.
With regards to Panel Memories/Registrations - with the Ketron AUDYA, it is our BLOCK REGISTRATION (which can be made up of single registrations [Song/Panel settings], MP3s, Waves, Midi ..etc). You can store 20 settings (the KN has 24 as you mention above) per Block REGISTER and instantly recall either with the F1-F10 panel buttons (one you press the REGISTRATION button and call up the BLOCK you are interested in), or using the footswitches as well. The good thing here is when you press the REGISTRATION button, all your Song/Panel settings are listed in the middle of the screen ... simply scroll up/down to the one you want to load and press ENTER (or just key in it's numeric value ... eg 102 to instantly recall it). The corresponding 1st 10 settings will be displayed adjecent to F1-F10 screen buttons (the next 10 are in the next page).
The good thing here is you are not confined to panel settings when creating a Register. Single Registrations are used to call up entire song settings (text files, music/song files ...etc) - as you mentioned above, way less button pushing than some arrangers in today's market.