Just a little followup.
In my opinion, and based on my limited experience (at this time), the two best piano benches money can buy are the Hidrau (pneumatic) and the Jansen (gear). After using the Jansen Petite Artist bench for a few years and now the Hidrau (ergonomic top) for approximately 6 months, I prefer the Hidrau. The ergonomic top has helped to remove almost all of my lower back stress that was acquired from sitting at the piano bench for protracted periods of time. It really is a very comfortable piano bench. I've moved the Jansen bench to my work location where I play my Yamaha P125 occasionally during the week. If I was wealthy, I'd have a Hidrau at work also.
However, with that being said, I must give high praise to the owner of Jansen Piano Benches (Mr. Jansen) whom I've spoken with several times on the phone. Jansen is an American company with superlative customer service. My Jansen Petite bench had a slight noisy wobble in the mechanism. The video below exaggerates the noise, but you can see what I'm talking about.
Mr. Jansen spoke with me on the phone, sent me parts (for free), and I did everything I could to remedy the wobble, but was unsuccessful. Eventually, Mr. Jansen paid to have the bench shipped back to the factory (about $90 to ship it one way) and his craftsmen fixed it. I don't know how they fixed it, but it's quiet, wobble free, and even has new buttons on the tufted top (the paint/finish had rubbed off some of the buttons). Excellent customer service. If they only made it with an ergonomic top, I probably wouldn't need the Hidrau.