All my quilts (down and synthetic) are hung in garment bags in the closet. Each bag will comfortably hold 4 quilts, although the bags that hold my full length winter quilts are much happier with only 3 quilts inside. They don't compress beyond 'lightly compressed', but they are a bugger to get in and out if there are 4 of them in a bag.
I like the garment bags because they reduce the number of bins in my gear room, which is an issue for me since my gear room doubles as our guest room. They enclose the quilts with a handy zipper in the front that keeps them safe from dog drool and cat scratching. Honestly, I'd rather repair cat scratches than dog drool, but that's another story. And they keep me organized; I don't have to label or dig through stuff to find what I'm looking for. A quick unzip of the bag and a visual glance is all I need. Plus, of course they stay nice and lofted...until I cram them into a pack.
As an added bonus, they are usually cheaper than the bins too! Only real downside is they will fill your closet rod quickly. At least, if you have a minor quilt addiction like some of the nut-jobs around here.