Verksam is great!
I bought a red Verksam chair last year, and I've been very happy with it. The foam is very supportive, and yet very comfortable for long-term sitting. I use it when I work at home at my computer, and I sit in it all day with no problems. Terrific variety of adjustments, so everybody should find a setting to their liking.
I also spent many weeks looking for comfortable and relatively inexpensive office chairs at local stores, and they were horrible. I would lose circulation in my legs after just an hour in them. I also tried out the really high-end chairs -- you know, the ones that are around $500-800. They were great, but I didn't want to spend that much. The top-end IKEA chairs, like the Verksam and the Klappe, seem just as comfortable, with just as many adjustments. But I really didn't want to spend more than $200 on a chair, so I went with the Verksam. And at that price point, it seems to have no competition.