Good Composite->VGA converters for classic computers (& video games...)

[Josh Dersch]

Anyone out there use a composite->VGA upscaler for their classic 
computing and/or gaming needs?

I've been looking to shave a bit of space off my workbench and just use 
a single SVGA monitor instead of that and an old composite monitor.  I 
picked up one of these: http://www.amazon.com/gp/product/B000XXZQWQ and 
while it works great for certain systems (the C64 and NES, for example) 
it gets really confused by the composite signal coming from other 
systems (like the Apple II and Sega Genesis) and is unusable with them.

Anyone have any recommendations?

Thanks,
Josh