After buying a new sleeping bag, I thought I'd abandon the traditional compression bag stuffed with clothes and use a pillow. It's a bit on the thin side and the stitching was coming undone on my one when I got it. It fits nicely into the hood of the sleeping bag though and it easily rolls up into the small bag provided to be about the size of a waterproof mac, so it takes up hardly any space. I think it's not thick enough to be good value for money, but it does the job.
Bought this as gift but it has been used on every camping trip since - no more escaping pillows on the night as it stays nestled in the hood of the sleeping bag. Apparently - even though I have not tried it myself - should recommend to others!