I was unhappy with the length of the screws for the bottom plate rod holders and replaced them with longer (and larger) screws. I did this because the nyloc nut was not fully engaging the screw all the way through the nylon.
I've added flat washers where I could because the function of a washer is to help spread the load.
I've measured my axial play in the rod liner bearings for future reference if I have issues. I did this by placing the rod half way through each bearing and using a dial indicator at the tip, and applied light pressure. I got from 0.010" to 0.030" on the worse one, which seems pretty bad.
The Idlers at the bottom plate are a problem for me. I really think the bearings should be pressed onto a 5mm shaft to allow the bearing to actually to its work, however I installed them as suggested, and I have 2.75mm of distance from the top of my idler to the top of my pulleys which causes slightly misaligned belts and extra wear. I will remedy this later by either buying longer bolts or fastening a shaft as I said before.
I've been working my linear bearings for the x,y axis, and I have found that one is very slightly warped and another is more warped and this is causing the bearing cage to skip with light pressure. I'm still waiting to hear back from Dustin C. on this issue.
That's where I've made it too so far, how are you guys doing?