From what I understand it can make a difference especialley in hop utilization. I use a partial grain/extract method and have read about a technique to increase hop utilization. At the beginning of the boil add 1/3 to 1/2 of the extract, add the hops according to schedule, and then add the remaining extract with about 15 minutes left in the boil. Add it slowly while stirring to keep it from going straight to the bottom of the pot and scorching. One trick is to mix some of the wort into the jug and disolve the syrup before pouring it in. It seems to work for me. Good Luck.