panor
The keybed is incredibly realistic.

You forgot to mention the instrument compare to which it is "realistic". Since you are classical piano student, I guess you do not think that lightweight Fatar actions (modifications of which are used in almost all DPs from manufacturers without own keyboard technologies)  is the best piano action in up to $8k range...
 
Real piano action is based on gravity which in turn is bound to the mass. The second major problem is the geometry (key length). Both are very hard to trick. Most hammer action keys are no more then one half in length compare to real, they try to compensate with "virtual" pivot point. Lightweight actions (like in Arturia) also have unrealistic weight, they try to compensate with "light hammer". Till some degree there can be some success, but "realistic" actions have proper weight and length... this way they are no really just realistic, they are real