Think you will find it does not give a satisfying picture. Tried a similar device.
I've tried many. I'm mostly curious on what's on the inside.
But, I gave it a try with my C64, and the screen image was pretty decent, I would say better than what I got from SCART. I pulled the chroma/luma from a source further in than what was offered from the rear plug.
I'm considering moving even further in (closer to the VIC) but I don't think it's worth the effort with this VGA converter.
The quality of this image kind of ruins the point of it, but here goes. This my breadbox C64 in 1024x768@75Hz on a 17" LCD:
