I ended up using the 8 lb trigger spring only in the 2 gp100s I have as well as in 2 of the SRH's I used the wilson in 2 1-gp and 1 SRH and the Wolff in the other 2. The Wilson gives the lighter pull. I did not change the Hammer spring because it slows down lock time and I can use all the help I can, if you do change the Hammer spring you will however notice a much better Double action pull. GP100Mans combination gives him lighter double action pull with a faster trigger return, my set up slows up trigger return and if speed is important you may want the heavier trigger return spring. Also his other mods are a good idea as well.
As of late Rugers GPs and SRHs have been coming through with a little better trigger pull than in the past, at least on the few that I have seen.