Where it will make a difference is if you are making multiple quilt blocks with a varied number of seams in each block and you are expecting your blocks to match up in finished size and have points or seams match or your quilt to be relatively square when you sew it together. The best test is to check your seam allowance by checking the size of your finished product, just like the link suggests that PaperPrincess provided. Your thread weight/thickness, fabric weight and cutting methods all play a part in getting it to what it needs to be.