G73-R black definitely has noticably increased details, and imaging yet I think it is still up to personal taste, despite of the hypes. I personally don't like it in that I feel the height and depth are largely sacrificed to a extent the stage became less organic and less 3D. Stage height is the strong point of Riviera which I really admire, so I hate to loose that. I tried sooooo many tubes but always found myself going back to the stock. Maybe I'm different than others but I feel the stock sounds most organic, netural, and natural even it doesn't have the best cymbals, timbers, stage or imaging as other tubes. Therefore I guess the best way to is demo yourself to see if that is your personal preference.