Beyond the issue of play -- VF is generally seen as the best playing 3D fighter ever -- Toshinden which came out around the same time as Saturn VF kicks the crap out of it and anything else the Saturn was doing at the time graphically, which is where the argument as to Saturn's capabilities lies.
Or compare Ridge Racer on PS to Daytona. An in-house game from Sega themselves, Daytona is one of the ugliest arcade ports I have seen in the modern era -- in fact, that's probably an understatement; more like it is the most pathetic big-name arcade to console port graphically I have seen. AT least in the 90's.
Just two examples. I don't know if the Saturn had some awesome 3D power that was hidden within it, but I think it's obvious that if this is true it was just buried too deep.