We swapped out the LM8's that were on our x-carriage for some pretty cool pillow block bearings we got from Igus. They're significantly lighter than the metal bearings we'd been using and don't require any lubrication.
They also run quieter and seem to be smoother, both of which can't be bad.
I'm printing a hollow Spocktopus (despite seeing the awful new ST:ID movie I still like that model) to see how it works on a larger complex print. My previous test boxes all worked out pretty well.
I'll update this with a full pic of the finished print later.