What are important features in a listening chair

gtechaudio60 nailed it. At least in the budget category. I had a very similar version of this. Light weight. Space-efficient. Supremely comfortable. Not only comfortable, but supports my head just about perfectly without coming up behind the ears. Rendering, needless to say, the irrelevant foam commenter irrelevant. Again.  https://www.ikea.com/us/en/catalog/products/S99903929/

At the top of the cost no object category is the Eames. https://store.hermanmiller.com/living/lounge-chairs-and-ottomans/eames-lounge-chair-and-ottoman/1000...
But there's a hundred out there just like it, everything from $100 crap all the way up to better than Eames just minus the price tag. My fave is the Ekornes Stressless with Ottoman. 

I always thought this one version of the Eames looked cool:https://losangeles.craigslist.org/lac/fud/d/aluminum-aviation-eames-lounge-chair/6880860006.html

All the best,
Nonoise

+1 Stressless

It has to be a design that allows spikes to replace the original chair feet, so that it makes you mechanically grounded with the speakers when sitting in it. Especially beneficial with vibrations induced with higher DB's.
8^0   

Build style and materials is a personal thing, but the height it places your ears at is very important depending on the speaker type and design.

i.e. ESL/Planar speakers sound best when your ears are somewhere in front of the panels. (not above......... or below)

Box designs your ears should be close to level with the tweeter.  That's been my personal experience. 

My custom made Gilmartin Rocking chair.  Sized to my body and much, much more comfortable then it looks.  Since it was sized to fit me, it offers great back support.  Difficult to get visitors out of the chair once they sit down.  Also looks outrageous. (The chair at the top.)

https://www.pinterest.com/pin/55450639136286625/