Months ago, after printing out the original mock-up of the 998, and assuming the same 17.1" width as the designed-by-Outlaw RR2150 (with which the 978/998 share a similar front fascia, as noted by gonk), I calculated a height of almost exactly 6.5" including the feet, i.e. approximately 6" for the faceplate and 0.5" for the feet.

It's virtually impossible to accurately estimate the depth from the newer pics of the 978; I'm still hoping for no more than 16" including all front and rear projections, as I requested in another post quite a while back.