Marketing on Slashdot again, huh... *sigh*
The Cherry MX Green does not feel like a buckling spring from the Model F or Model M keyboards, really.
While it is a stiff clicky switch, it is far less tactile, and the tactile point is different.
The Buckling Spring on a IBM Model M or Model F has a slow progression in resistance followed by a sharp drop at the actuation point at around 2/3 - 3/4 way down the stroke.
The Cherry MX Blue and Green have a small bump at the actuation point, which is higher up, at about 1/2-way down the stroke.
As other posters have already written, the MX Green is just like a MX Blue with a stiffer spring. It was made to be used for the Space Bar on a keyboard that is otherwise populated with MX Blue.
Compared to the Blue, with the Green's stiffer spring you tend to press harder on it and that diminishes the feel of the tactile bump somewhat.
The Green has always been used as the space bar switch on Cherry's own keyboards with Blue switches. The only new thing is that it is used on a whole keyboard.
Having a stiffer switch on the space bar is common. Ordinary rubber dome keyboards often come with coiled springs under the space bar to make it stiffer.
If you want a Buckling Spring keyboard, you could buy a new Model M from Unicomp. They are built using the same machines and tooling that the old IBM keyboards were. They even cost less than many gaming keyboards with Cherry MX switches.
BTW. This post was typed on a Dolch keyboard (Cherry G80-1813HFX) with Cherry MX Blue switches, except for the Green switch on the space bar.