The latest offering to come out of the ZOTAC factory is the 8400GS, Nvidia's current low-end DX10 part. Priced relatively low, you can tell the card is for a certain market of people who really don't want to spend the big bucks or simply can't afford to.
The good news is that low-end cards have become better over time, to the point where they are a reasonable upgrade from onboard graphics equipped motherboards.
The high-end 8800GTX AMP Edition from Zotac really impressed us last time, and it shows us that Zotac can be a competitive force in the VGA market. Though in order to survive there is no doubt you have to be able to turn out a high quantity of low-end cards.