From the description on YouTube:
This set provided a 25" picture (measured diagonally) at a time when most sets offered 10" or less.
Many believe that early rear projection sets fell out of favor due to their poor, dim picture quality and limited viewing angle.
Watch the video and judge for yourself.
I believe their downfall was their large size, their weight and their high initial setup costs. Eventually of course, direct view picture tubes caught up to them. But if you had deep pockets, you were watching a 25" TV several years ahead of most folks!