4329 just purchased an X-Carve a few weeks ago and is in the process of assembling it. We also bought the 1000 mm variant and basically went with the 'provide us everything' option which runs around $1500. While we hope to have this supplement our build processes, we're also hoping to use it as a way to get more kids excited about learning to design in CAD similar to what 3D printing has done for us.
There is a significant amount of information on the Inventables forums on making the 1000 mm machine more rigid for each axis. For the X-Axis, the main issue comes from each maker rail extrusion bar being supported by only 2 screws on each plate. With no supports in-between the two rails, this can allow for flexing especially when cutting harder materials.
A pretty quick and easy solution is to just put some kind of material between the two rails, detailed in this thread:
https://discuss.inventables.com/t/wi...kerslides/9448
We're trying the solution of 3D printing support ribs and placing them throughout the two rails -
http://www.thingiverse.com/thing:503437
Basically any question you have has probably been answered on the Inventables forums, I'd highly suggest spending an hour just researching stuff.
We plan to post a short white paper detailing our experiences with this machine and hope to have it ready in December.