It might be better "borrowing" a Component lead first, since you spent so much on the Svideo lead. This way you could decide if the change wil be worth it.
I was using a "Vivanco Prowire" 10 metre Svideo lead. Svideo doesn't travel so well over long cables. The Sony does have a very good Svideo input decoder. So the high quality one you bought might not lose as much info as mine did etc.
The difference wasn't night and day as such.
I just found after swopping, i started noticing so much extra detail. Plus the picture had more "punch" and "3D-ness".
Going back to Svideo after a week "just to see" was like looking at a "photo copy"!. The picture went flat, and detail seemed hazy.
It was well worth the money "IMHO".