The following is the extruder I printed the same day I designed these parts and rendered the above image. Now this is progress!
The aspects I'm most excited about with this new design are it's weight and center of gravity. I would wager it weighs 1/3 as much as my existing extruder, (something I will test when I switch them), and the center of gravity lies right between the X guide rods. I'm hoping this will allow me to increase the speed of the print while maintaining quality.
I bought a tap a while back to put teeth into the bolt as Wade describes here, but the tap was too cheap to cut into the steel bolt. I purchased some high grade taps from WTTool today and hope to get them this week. With these taps I'll be able to finish the bolt teeth, which is the last step in making my new extruder. I hope to install it this week.