In my experience TIGER is pretty accurate as far as having lots of roads and locations of the roads. Plus, TIGER has a lot of other information as well like political boundaries, national forest boundaries etc..
As far as accuracy- all map data suffers from "road drift" where it looks like your driving off the road (in places). The biggest advantage to a commercial map platform is the one-way aspect. Besides, TIGER can't be all that bad because some commercial vendors actually use it as a base for their maps (StreetAtlas).