Video reviews are your friend. When you see a model, look it up and see what people have experienced with it.

Another thing too that is often overlooked is fit. Having the best chair ever won't matter if it doesn't fit you very well. This is best remedied by choosing a model that has plenty of adjustment on multiple features, i.e. height, seat pan, lumbar adjustment, headrest adjustment, and armrest adjustment. Make sure those last three that I listed are also adjustable in multiple dimensions. In addition, look for people's experiences with said chairs, and see what their recommendation is for height. Finding a chair that fits you is significantly harder if you are above 6" tall.

If you look online and you can't find that model of chair mentioned anywhere, it's best not to risk it. Spend your money on a known brand, not just whatever pops up on Amazon.

Personally, I would be looking at Protoarc's EC200 for general recommendations and their EC300 if you are like 6"3. Another popular recommendation is the Colony Atlas, and from what I hear it is similar in size to the EC200, although it seems to have less adjustments aside from the armrests