First, the Varidesk lifts with spring action, which is much harder to raise and lower than the Flexispot pneumatic assist. Several of the shorter/average height women in the office had a lot of problems raising the Varidesk, and some could not lower it. The FlexiSpot on the other hand was easy for all to raise/lower.
Second, the base of the Varidesk is deeper, and hangs over the desks in our cubes, while the FlexiSpot fits perfectly.
Third, the Varidesk moves forward when it raises, so the unit becomes top heavy, particularly with the overhang of the base. The FlexiSpot raises and lowers straight up and down so stays more stable.
Fourth, the Varidesk has more cutout area, meaning that the FlexiSpot has more real estate for monitor, laptops, paperwork, etc. Finally
Overall, the FlexiSpot, after side by side comparison with the Varidesk, is clearly the winner. More stable, easier to raise and lower, more real estate, and $100 cheaper!