These columns are as rigid as you can purchase for the $
There was a problem with the old model such as mine in that the dove tail area got thin enough to flex under load of the saddle gib and the weight of the gear box. Gene heard what I had to say about it and very quickly incorporated the new design as is available now. This greatly reduced the flexing and made for a much more stable design, also as part of the upgrade he did, the saddle covers more surface area and should prove much more stable.
As for rigidity in the total of the form, You could put an indicator on the gear box to the table and push the top of the column with your hand and see a small deflection. But, It may show up in roughing but that is why we use a finish pass ! So, in effect this is a non issue !
For the money I'd be prone to say it is a very rigid design and plays the effective role in productivity.