Hitachi revisited

RE>HITACHI REVISITED: I ve read with some interest about the Hitachi makeover that earwigger performed on his X-carve. I would like more details about the actual performance on the 1- original duel rail system with the steel insert, 2- about the new makerslide rail system and finally about the Open Builds rail system if possible. What I am after is the amount of sag and lateral twisting in the rail system themselves. I would also like more details about the Z axis. I have the Zenbot mount with the thick base plate and would like to keep it as is. Would the basic Z rail system support the router and mount with a 175 oz/in motor. I also have a 5 to 6" linear r system laying around some place but that weighs about 4 pounds. I will reinforcing the Y axis. What I am after is actual numbers and data. THANK YOU!