well the problem with injection molding is, as BLJ said, the surface of the mold has a lot more to do with the friction characteristics than the material. thermosets are a bit easier to get a smooth surface on but the ideal thing is to hand or machine finish the surface to be smooth then lubricate it with, for example, the most advanced polymer lubricant ever made. the advantage of the thermoset version with the pre-preg oil for lubridicity is that it is a solid, so for situations in which the material is exposed, it will be more durable to use the pre-preg solid.
however, if your slider is enclosed, you can just use a bearing joint grease. so basically if you want smooth linear sliders you guys are doing the optimal thing, and as much as my dupont rep is incredibly shocked that you guys put the effort into it, he is quite happy to point out that you get an optimal surface that way.