You have it backwords, doom 3 has the better textures (combo of specular map, bumpmap, and texture) but the game is made using very low polygon count ... I have heard it is allmost as low as Quake 3.
The poly counts arent that low. In 2002 we've heard that the characters will have from 2000 to 6000 polys. I think thats changed since the newer shot of the pre 2003 characters look much more detailed and the polygonal edges dont show nearly as much.