RSX has half the ROPS and half the bandwidth, a 7800GTX would eat it for breakfast.
A 7800 GTX or any PC videocard for that matter will still be limited greatly by the API being Direct X and Open GL unlike a home console like Playstation 2 and PS3.
Microsoft and the Open GL board do not make graphic processors, ATI and Nvidia do, Matrox, S3, Videologic, and 3d labs used to so beliveing that a GPU will be limited by cut down hardware from a PC part is alot like believing Direct X marketing hype from Microsoft.
Now its true that PS3 uses a custom version of Open GL code that can be ported to PC if the developer feels like it and it may as well be able to use Direct X dev tools since the GPU comes from the PC side of things but doing the latter is probably the reason some like to use terms like "lazy developers"
The engineering decision to go with 8 Rops and 128Bit bus may also have alot to do with technological limitations for a product that would be expected to have a high penetration in homes world wide and in different temperature and power consuming zones.
I do love the idea that many keep wishing for having had a G80 instead though, specially when things like power consumption and heat thermals don't seem to be considered, at 90nm it would have been impossible for Sony to ask to have a 680 Million transistor GPU and at 65nm it would have been a bad engineering decision since it would have made more sense to go with G92 but so what? the console would have been more powerfull but it would have been released in 2008 realisticaly and by then Nintendo would be going for a 2 year lead and XBox 360 for a 3 year lead with price drops and fence sitting gamers breaking down for one, it would have been unpredictable and unlikely if people would have really been willing to pay for a PS3 launched in 2008 instead, even with undisputed technological power.
I personally feel that Sony and Nvidia made the best possible choice in basing the RSX on Nv47/G70 and the fact that its Sony, NOT TSMC that is fabricating RSX GPUs leads me to believe that Sony was being very carefull to make sure that their GPU would work to the best of their specs and not come out half baked out the oven.
Its amazing to me that the PS2 graphics chip would at best be considered a 1997 or 98 ish level technology that benefited from process shrinks to launch at the desired clock speed and I see the same happening with RSX being that Nvidia's Nv30 was considered a failed design (for PC use) and Nvidia worked hard to make Nv35 a much better, more efficient performer that by the time they made it to Nv40 they managed to best their last effort twice.
I wouldn't use Yakuza 3 as a power meter for RSX/RSX + Cell. The game looks like a launch title with medicore graphic (technically) but great art. Pre-baked shadows/lighting, projected shadows etc. I think Killzone 2 or Resistance 2 could be used for that or Lair.
As for Ryu Ga Gotoku Kenzan (Yakuza 3), here:
http://gamersyde.com/game_1378_en.html
They have 1280x720 resolution MP4 videos that I have downloaded, put in a key and put into my PS3 to basically see the closest thing to running the actual game.
Now Lair as impressive as it was at rendering geometry and effects, to me it was doing a fine job at rendering objects that will mostly be seen as being coming and going from far away distances and to be fair that was Factor 5's first effort
KZ2 and R2 are just FPS so even though the detail will be impressive its still is stuff that comes and goes but you will be really too busy to notice the details since you are gunning and running for your life, Yakuza on the other hand has objects that will come and stay for a while and will have to be convincing for the dramatic scenes where the graphics so far have displayed a great direction and on top of that the game also has relatively fast action with reguards to its fighting engine, I don't see this being possible as some kind of launch title with mediocre technical graphics in no way just like Shenmue and GTAIII needed more than one year since their consoles hit retail for release.
Of course since Yakuza 3 does not feature an armored westerner holding a rifle or a hooded assasin with sharp hidden blades it may have a hard time appealing to most people outside of Japan and maybe Asian countries since the game deals with a historical setting that may seem alien to those not familiar with it or used to seeing it but I don't think that it stops the game from being impressive as a first effort, then again I am not sure what you would expect an impressive effort would be, that all games become FPSs?
As far as the cultural divide, I am even sure the game will be dismissed specially with GTA 4's appearance, specially with that game being on two competing platforms and its more modern, western setting but people will be marveling at its graphics.