Which is better, ATI USB 2.0 or ATI HD 600 USB?
 

I think ATI USB 2.0 is the grey block with a big red logo which I believe has 12 bit analog to digital video conversion.

ATI HD 600 USB is the more dongle size unit, much recommended, which I believe does 9 bit conversion.

I see early posts years old describing ATI HD 600 USB more as pretty good but it's reputation seemed to grow much bigger since. If I obtain the big grey ATI USB 2.0 unit, can I expect a better conversion than 600 USB unit (all using TBC of course) ?

There are versions of the "grey block", with very nuanced differences. Most come with no software, but there are two distinct driver discs for it. Don't random buy these from eBay, you'll get screwed.

I can't write more now, back later.