I tried the feather and down, because it was natural and after 10years, I got fed up of being too cold in bed to get to sleep, then too hot in the middle of the night.
I am quite happy with my upmarket supermarket microfibre one. I was looking at the wool ones and silk mix ones. The microfibre one caught my eye and at £45 (they were more last time I saw them) for a king size, it was worth the risk. It is instantly warm, unlike the feather one, and softer than the hollowfibre, so that it does not leave such big gaps round the edges.
When I had mastitis a lot, whilst breastfeeding, I used to get drenched, and used a good quality cotton top sheet as well to soak up all the sweat! I could chuck it out in the night if it got too wet.