An excellent office chair and great customer service.
I had a Secretlabs Titan, but it was giving me severe leg pains, and so after some research I decided on a replacement and bought the Doro C300 Pro V2. I'm very happy with the chair. It has an almost crazy amount of potential adjustments, and shifts and moves well with you. It also feels very good quality - sturdy materials and holds together very well once assembled. (Be aware it arrives in two packages and they may not necessarily arrive on the same day due to logistics.) The customer service has been excellent, too. I'm 6ft tall, and so found the chair is very slightly low for me to be fully comfortable, so I contacted Sihoo about this and they sent me a taller gas cylinder to help with this. Unfortunately the chair is SO well put together that I can't get the existing cylinder out of the connector that the legs attach to, but their customer service has stepped up again and are sending me a new one of those as well, so I can't fault them for their responsiveness and willingness to help.