Other reviews imply that whatever "complications" users may experience stem from not reading the "instructions"--which consist of one sheet of common-sense one-liners: "put feet flat on floor" etc. Stool has no back, obviously, so you may feel unsupported. Working at a desk helps minimize wobbling because your arms have something to lean on. Not intended for long-time sitting but to give the body a break from staying immobile for too long. Is nominally 20" tall but will compress to ca. 17" (normal dining chair height) when sat on. A very tall torso may be harder to keep erect and very long legs may strain hip-knee relationship.

Pros: Although made of plastic, sitting does not feel abnormally warm or cold, or too hard.
Cons: Has a seam all around the sides/top/bottom that COULD split after time or abuse. Removable plug on bottom could leak if damaged.