DP's will decrease your spool time, especially if they are split/divorced DP's. The gains in power or the decrease in spool time will be marginal, the spool time will be slightly noticeable but I doubt you will see 30hp gains like someone said earlier on stock turbos. I would also keep in mind that some turbos are 4 bolt and some utilize a 5 bolt DP. You may want to be sure what turbos you are going to upgrade to. If the turbos you are considering use a 5 bolt then I would just wait to get both at the same time instead of wasting money on 4 bolt DP's if you are upgrading to a 5 bolt turbo within the year. If you are upgrading to a 4 bolt turbo then by all means have at it. Just makes sense to plan ahead a little.