I'm 5'10" and hubby is 6', and we both weigh around 220lbs. When we first sit on these nice big seats, the hydraulic drops the seat a small bit, but then stops securely. I've come to the conclusion that it's a common hydraulic feature to do this, to sort of give a cushion. I was hoping the base, the disc on the floor, would be a little more heavy-duty. You can feel a slight amount of play when you lean to the sides a little. But the stool is surprisingly lightweight, and that would be sacrificed if the base was heavier, so I think they have found a good middle ground on these points. Oh, and the assembly was a piece of cake.