The additional 10mm rod on each side of the z axis is a tremendous advantage. The upper brackets are muck beefier which helps keep things square and makes the entire frame stronger. I also used 10mm rods in the "y" axis, with four linear bearings. The carriage ends are twice as strong as the more typical ends too. check out the carriage end and the 4 bearings in the end. It's super strong. The pair of 5208zz bearings on the upper z axis really helps deal with z wobble. I hope this helps.
All makes sense. Can you share the .stl's for the enhancements? I like the idea of stronger and less wobble.
Hi Diggerj - check out this link on thingiverse. It's where I got most of my files from to make this. http://www.thingiverse.com/thing:466241 The y axis I used was a wider version but I can't find the link for right now. It's almost 8 inches between the rods. It also came from thingiverse. Enjoy!