DC has offical support for VGA box, can go up to 640x480 on monitors (if i remember collectly).
PS2 doesn't offically support VGA output, so, no performance boost, or should i say no high resolution game play.
i own a
Redant VGA box,
it plugs directly into your PC and to your monitor, auto NTSC/PAL select. audio in and out, and enable the YPbPr (can't see any difference...)
but it also takes one of your memory card slot for power.
and there's a line on the monitor when the VGA box is off (auto back to computer screen), it's like a bump...
they are rare on ebay(expensive, i got it for $40-50), lik sang has some other brand, don't know much about them...
that's about it...goodluck and enjoy shopping~