Yes. And in the few (mainly Adobe) desktop applications that do/can use variable fonts, I know of none that can properly turn out a valid pdf for printing purposes. Same goes for color fonts. QuarkXPress is the only application I know of that can use them properly. And it can use 3 of 4 types versus 1 type in Adobe applications. Adobe warns about using them and expecting proper pdf output for either font technology at this time.

The axes in the variable font spec are still not all static, the spec is still being revised and axes are still being registered. Until the spec becomes more concrete, and unless an application only exposes certain axes to the user that are "stable," I don't see the technology being anything more than what one Adobe person who is involved calls them: Experimental.

Certain axes do work fine in browsers.