Any suggestions? Looking for something that will work well with sateen sheets in both summer/winter, but something that will not bunch up the sheets on a King bed when it's made. Would also be great if I could fit it into a washer too for cleaning (Miele, shortly!).

Cuddledown has a few on sale, but I'm worried they will either be too thick and overwhelming and/or not fit in a washing machine -- issue with the current featherbed topper which is too much. Looking for something comfortable, but also simple and manageable from a laundry perspective.

Any ideas? Thanks!