I don't know who's making up these distinctions, but "enthusiast" or "performance" is usually a synonym for a high end card, by companies at any rate (I think most people would just call it a high-end card). Maybe this site you're visiting is using somewhat non-standard language to describe them.
Not really............ notebookreview.com is probably the leading community now for notebook-related discussions.
On the notebook side at least, a distinction is made between "performance" cards and "high-end cards".
Usually that's because there's a difference in what is high-end in something that is still reasonably a "laptop", and those crazy 12 pound "laptops" with SLI 7950GTX Go setups and such.
-Zadillo