Howie is right....top loaders work fine, since that is what I have as well. Just make sure you do the stuff sack trick, or you'll be wrestling a big, heavy, puffy, mess.

One way to keep your bag fluffy in winter is to leave it out on your bed, unzipped, as a comforter. My trusty 25 year old TNF Chrysalis is still my favorite bag and just as puffy as ever....been washed/dried at least every couple seasons, top loader, no special detergent, high heat. Down is amazing stuff!