Over my working life I've sat on many chairs. As a consultant you have to make do with what the client provides, but since I've become permie, I've been campaigning for a standing desk. Recently I got my wish, well, in part.
I don't get on with the chairs at work. They are not cheap ones by any means but by the end of the day I can really feel my neck and shoulders suffering. I'm not sure what it is with these ones in particular, I just don't get on with them. My cheaper chair at home is far better. I've actually been using a kneeling chair for the last year or so and that has been great, it really forces you to sit up straight. Its a little tiring at first but you get used to it, and I don't get the bad shoulders or neck that I used to get on the chair.
But like I said I really wanted to try a standing desk.
I managed to persuade the people that matter to give it a go and so between us we knocked up an IKEA hack standing desk made of coffee table and shelving unit (low budget experiment ~£30).
I can use it all day but I find my feet and legs get sore mid afternoon and I really need a sit down. The desk is a long way from hydraulic and its a very big faff to put all the stuff down on the desk so I've sacrificed my second screen in a mirrored set up so i can stand and sit as i please. I tend to do the morning stood up then split the afternoon alternating sitting and standing as I feel the need. It's a compromise and since the screens are big I can work split screen rather than multi monitor without losing too much.