I think that Voltz is missing a mod from normal Tekkit. The mod of course is redpower. I feel the ability to place red alloy wire vertically up walls is a major plus along with all the other things, pipes etc. Also i am finding it IMPOSSIBLE to build a large missile silo with an opening roof without frames. Possibly the most important aspect of the mod.
I would like to ask the makers of the Technic launcher to please include redpower in the latest Voltz update as i think it would be a major plus to the mod-pack. I think many others feel the same.