I applied for the FAST certification during orientation, too - not for more money, (it wasn't offerred, & so far, the program has cost me money), but because it sounded like a useful credential/tool/weapon in the effort to convince the US border officials that an American-born citizen, driving a commercial vehicle, on behalf of a well known American transportation name, probably isn't a suspect for terrorism, smuggling, or whatever other felonious activity they are charged with preventing.
Since being presented with my FAST card, I've crossed the border 4 times, and the score is: Border officials:4, FAST:0.
None of the loads was FAST certified, (one shipper said the regs for the company to get certified weren't worth the hassle, unless shipping frequently into Canada.) I couldn't have used the FAST lane even with a FAST load anyway, because I am still waiting for the carrier to send me the transponder. The one I didn't even know existed until I read about it right here on EO...
Anticipating a FAST improvement in border crossings has turned out to be a FAST reality check, for me. x(