In my opinion this is definately not true. 800*600 isn't a high enough res to display Vpin properly, especially on the more complicated tables. But as Xiaou2 said most cards now display 1024*768, which is a big difference. I couldn't stand vpinball on my old ati with 800*600 out, but my new radeon that does 1024*768 does a great job.
Err... I'll admit, I haven't made the comparison, but I have to question this.
A standard TV has to have
everything scaled to a resolution below 800x600 for it to even be displayed.
Even at 800x600 you aren't viewing the true resolution of the source, but something that has been downsampled to fit the 720x486 native resolution of the TV. Unless there has been some major developments in the scaling process, I find it hard to believe that it would look
that much better at 1024x768, as the final result is still at the native resolution of the TV.
But I'll hold final judgement on this until I compare it myself.

BTW, Vpin looks just fine to me at 800x600 but as stated before, not at 640x480 as it is under the native res of the TV.
RandyT