I figure that's why I took all those stretch-and-sew classes so many years ago. I use the same technique to make my quilt squares line up. Seems to work fine, but I'm not the perfectionist some quilters are. I would definitely hate the process of having to square up all the blocks. I don't think I could ever get them square anyway.
I also don't try to square up a quilt when it's finished. I try to cut the corners at 90 degrees, but I don't stress over it. When thrown over a bed, who cares?! My wall hangings seem to look fine, too.