I was wondering how efficient are the quadric functions built into OpenGL (gluSphere, gluCylinder, etc.) and should I be using them to draw primitives for a game?

I think that they are good for tutorials or simple applications. But for games would I prefere creating your own objects with the glVertex or a similar commmand.
-This gives you control over every vertex of your world and that can be usefull for animation, texture mapping, texture animation and special effects.
-You can then create quite simple code to save and load the position,color and texture coördinaat of every vertex in or from a file.
-You are not forced to use the standart forms and you can create every form you can imagine.