why would the 007 give more power than the split R?
See this is why i should of stuck with a corsa haha
a 007 (forge 007p) is a diverter valve that does not dump any of the air to atmosphere (all air is recirulated).
The split R is also forge but dumps to atmosphere a part of the air but recirculates most of it.
The ecu does not like air being dumped to atmosphere, so the split R is designed to create sound but keep enough air recirculated to keep the ECU happy.
Neither give you more power as neither are anything to do with power.
Compared to a standard DV they operate slightly better, faster and therefore may give a better gear change.
My advice would be the 007, its cheaper, does whats expected and the money you save can go to an induction kit which will create more sound using the 007 than you would from using a split R.
Regarding the post with someone who changed from a split R to a 007 which transformed the car, id say the split R was not set up correctly or had a leak, the differences between the two would only be during a gear change, and would be so small they would be very difficult to detect.
If a DV was leaking when on boost, (it should be closed/sealed at this point) then this would effect performance as you would be losing boost.