Having assembled the Ender myself I think I know why some CR-10s have the Z issue and some don't - there is quite a lot of play in the bolts which hold the two Z carriages to the X axis. If those two carriages are parallel to each other but just slightly off perpendicular to the X it will all want to sit slightly twisted. The steppers can hold it straight when they are powered, but as soon as they aren't it will jump back to the twist which is exactly what mine did.
When I put those two parts on the Ender I was very careful to get them as perpendicular as possible to the X axis, and the Ender doesn't show any twist at all, even with just a single Z rod. Its done a dozen prints now and I haven't had to touch the bed level at all. Just pop the build sheet off, bend it so the print pops off, put it back and start the next print. That's what the CR-10S should have been like! I guess I got a Friday afternoon build
I'm really stuck on what to put on the CR-10 as far as the extruder goes. Hotend will be an E3Dv6 since that's pretty much the benchmark. But, do I do a bowden with the existing extruder, bowden with a remote Titan extruder, a direct-drive Titan, a Titan Aero, or even a Flex3Drive extruder with E3D hotend
The Hypercube is getting the Flex3Drive without a doubt since that's the ideal solution to a light print head which can do flexibles. But, I'm not sure the CR-10 really needs that since it's speed limited by the big glass bed so a direct mounted Titan probably wouldn't slow it down at all.
I might just do a Flex3Drive on the CR-10 as well to see how it performs while I'm building the 'cube.
Just can't decide. Argh!