Composite vs. S-Video vs. Firewire?

[Lord Sandwich]

Given that the source is DV, is there any real difference in capture quality between these three inputs?

I know Composite has the worst picture quality in theory, S-Video is much better, and DV is pixel-perfect to the tape, but I've never seen a side-by-side comparison of the three. Hell, I don't even notice the difference between Composite and S-Video! :D

I capture at up to 768x576i with a BT878 card; does it really get much better than this? Enough to justify a $1,000+ Matrox/Pinnacle card?

[Cart]

You can buy a firewire board for DV for $50 US or less. You should get lower noise, better color, etc. with DV. I've never seen a side-by-side comparison either, but I imagine the ease of use and video tuning would be worth it alone.

-Cart
http://www.geocities.com/lukesvideo/index.html

[Lord Sandwich]

Yeah, I suppose I'd buy one myself if my cam and TV weren't different formats. :) Still wish someone had a comparison guide, though. Instead of just comparing cards of the same input type.