I use Space bags all the time. For storage and for mailing and shipping.
The trick to avoid wrinkles is to fold them on the diagonal. The fabric gives and moves on those lines. When you open the bag again there will be no wrinkles. If the quilt looks a little flat a few minutes in a cool dryer will plump it again.
I couldn't live or manage shipping costs without those bags. I don't use expensive ones, just the selection from the local $ Store.
MaryKatherine