Few things are as comfortable as a good office chair. Few things are as miserable as an uncomfortable office chair.
Lumbar support and comfort are nearly equal on the ladder. Since sitting at a computer for several hours a day puts strain on the lower back, a good office chair should have adequate lumbar support. This should not feel like a large knot in a chair’s back. If it is unobtrusive, yet supportive, it’s perfect. It should also be in the correct place. This may sound obvious, but it’s not. People of different heights have backs of different lengths, and the lumbar support should fit that person’s lumbar area, not be above it or below it, more in the sciatic area.
Comfort is also key. An office chair should be soft enough for comfort, but firm enough for support. It should also be wide enough in the seat to support the hips.