My baby had a flat head, as she would only sleep on her left. I spoke to a doctor and a physio. We had a selection of excercises. However my physio was impressed with the fast improvements in her head shape. I said that I actually cheated and ontop of the excercises I used the "love nest" pillow. She NEVER slept with it. But I ALWAYS used it when she was on the play-mat or in the pram. The pillow in the pram made sure she did not turn to her favourate side all the time.
The hysio was so impressed with her head shape improvement he asked me where I got the pillow, as it may be a good item for other of his patients.
The pillow will have little effect after 6 months, as the head of the baby is harder. But it has great effects before. The head shape at 7 months is nearly normal.
I think this is great - as shown by my baby's improved head shape (it's not perfect - but nearly there, as you cannot see her flat side).