I've had nothing but actual chairs for years. TBH? I would never define any of them as totally comfortable. Not like a big leather sofa hugging you comfortable. However, since switching to proper chairs (instead of gaming cack) I can say that I have had no bum aches, no back aches and my posture is forced well.
My last chair was a Herman Miller Sayl. I got it about a week old. Had it for a couple of years, then my ass got fatter (sodding pills) and so I got a Humanscale Freedom Headrest (£1200 worth of chair for £240, completely refurbed new cloth, painted the frame etc).
The biggest test of any chair ever made is the bum foam. Crap chairs will give out and you will be sitting on plastic/wood whatever. A real chair never changes in firmness and never gives out.
Because of that when I needed another chair I bought a refurb Steelcase Let's B for about £60. New cloth etc. Not as nice as the Humanscale (it's a bit looser) but I would take it over any crap gaming chair.
Going to shift it to my mother's soon and set up camp there.