Ok, so its a bit pricey, but its worth every penny.
Having so many adjustment levers (3) and knobs (2) means you can quickly and easily get the position that's just right for your playing. Literally everything is adjustable - even the angle of the seat!
It arrives with static feet (not castors). There are also no instructions of any kind about construction (arriving in 2 sections) and use, but fortunately its pretty self-explanatory although working out what the levers did was fun! If you're not familiar with office type chairs you'll enjoy working out "do I twist or pull this one and what does it do" etc!
I had previously been using various guitar stools, barstools, kitchen chairs(!), office chairs etc but I needed more support for my back and this chair provides it.
Be aware that it comes in 2 versions: this one (B1024) adjusts the seat lower to the floor than the other (B1025). Its also available in 3 colours but I think Thomann only do the black.
So, in summary, I'm very pleased with my purchase. It makes guitar playing much easier. Its probably a bit heavy to take on gigs unless you have a roadie! HTH