The Sweet Spot has no provision for the trigger return spring. That's okay, because you don't need it and deleting the spring will reduce the pull weight.
With the trigger return spring deleted and the Sweet Spot adjusted properly, you will notice that it is easier to shoot fast. I was skeptical before I installed mine, but it felt much better.
The Sweet Spot does not reduce the side to side play of the stock trigger. You can get rid ot this slop with a small plastic washer on one side of the trigger (pivot pin through the washer). Simply rub the washer on some sand paper until it is snug, but not so tight that it drags on the trigger (sand, test, repeat as needed).