S-video from Sony CXA1145 - how good is it?

[PCEngineSales]

I'm thinking of s-video mods using various chips but this one seems to be the easiest to get hold of at the moment. You can rag the CXA1645 out of a Saturn but the price of a broken saturn+postage off eBay pretty much defeats the object of this (postage cost being the main issue.) I have the Sony CXA1145 on hand and I wonder if there is any difference in image quality? Does anyone have a schematic for the 1645 mod - I assume the 1145 is the same pinout, same circuit.