I have had neck surgery and still have neck pain. I also have lower back pain. I've found the best thing is a combination of sitting and standing. I do my cutting and ironing standing, and my cutting table is in the other room so I can get some circulation going.
My lower back will definitely act up if I do not tuck my hips under to prevent my natural "sway back". I also have to concentrate on dropping my shoulders and sitting straight because of my "hunch back".
When I worked customer service on a PC all day I was SO thankful to be able to lift my whole work station to standing level. When I get used to correct posture I think I will arrange to stand while sewing and quilting too.