I have always pin basted my quilts, THEN hand basted them in a grid. I then took the pins out and did my quilting. I don't mind taking the extra time to do that to my full size quilts. I think I only spray basted one full size quilt. I do spray baste my smaller projects. Sometimes I don't get to finish machine quilting a quilt all at once (depending on how much quilting) so I like to hand baste. I also love to hand quilt and well the spray basting just won't stick as long to finish those.
When you do spray baste, be sure to put down a cloth over your floor before you put your quilt down so that you don't get any of that basting spray on your floors... Its a pain in the butt to clean off of hardwood floors!