the 7-pin vs. 4-pin question
I was looking at my laptop yesterday, and I noticed that the output for s-video is a 7-pin... But I've plugged in a 4-pin before, and the video came out fine.
In response to your question, I also looked online, for almost an hour, and found absolutely nothing that actually stated the difference between the two.
Your best bet, and what I'm going to do first thing monday, is call up my laptop's manufacturer (dell) and ask what the difference is. I'm assuming that the 7-pin is made with some sort of upgradability, or maybe just so that people will have to buy adapters?
Couldn't really tell you, but, like you said, the 7-pin must be better (why would there be more pins, right?)