The AVID machines are quite capable. I helped my buddy order a few parts from 8020.net to reinforce the exiting structure (extra extrusions, cross-members, gussets, etc.). I think he spent about 300-400 on parts/shipping and it made quite a bit of difference after we stiffened up the base.
I think that's where the steel welded machines have a huge advantage, but it comes at a real cost in $$$ and weight!
Remembering ...
I think just the 16 footer ... we had a custom Z axis with 16" ... plus? of travel?
Rapid traverse, with the weight of the spindle way up there was possibly overloading the 'trucks' on the linear guides. I kinda remember seeing a few small ball bearings laying around before I left ...
I think the 4x8 we extended to 12 feet had the v rollers
https://pivotal.aero/
I did the first couple of molds for the fuselage on the 16 footer. It didn't need that much, but we'd extended the wings past the capacity of the original 12 foot machine.
190k ... I'm pretty sure my dad would have sold me his Bonanza for a whole lot less... annual inspections, fuel, tie- down ... and now I'm across the street from the runway in a private airport community. Just hearing them is enough.