Hey Tony, thanks! Yeah, as you said, it is difficult to get good stiffness over such a large range of travel. The machine's certainly not churning out hardened steel parts or taking big cuts at slow rpms in steel, but for the occasional prototyping part and the kind of tinkering stuff we do, it should work out well.
It is actually running Samsung AC servos, so yeah, closed-loop all the way
Thanks again, Bongo.